Thanks @Apachez,
I think you may have hit the nail on the head.
I’ve re-tried tonight via add system image from 1.4 to 1.5 rolling, removing only listen-address post boot and all appears to be working 
Post reboot testing across different vlans/subnets with dynamic pool and a static (100.98):
$ show dhcp server leases | strip-private
IP Address MAC address State Lease start Lease expiration Remaining Pool Hostname Origin
-------------- ----------------- ------- ------------------- ------------------- ----------- ------ ------------- --------
xxx.xxx.88.32 xx:xx:xx:xx:xx:8d active 2024/04/30 20:05:43 2024/05/01 20:05:43 23:45:04 LAN1 xxxxx-xx local
xxx.xxx.88.69 xx:xx:xx:xx:xx:c6 active 2024/04/30 20:05:28 2024/05/01 20:05:28 23:44:49 LAN1 xxxxxx-xxxxxx local
xxx.xxx.88.96 xx:xx:xx:xx:xx:31 active 2024/04/30 20:08:01 2024/05/01 20:08:01 23:47:22 LAN1 xxxxxxxx local
xxx.xxx.100.32 xx:xx:xx:xx:xx:fc active 2024/04/30 20:20:33 2024/05/01 20:20:33 23:59:54 IOT10 xxxxx-xx local
xxx.xxx.100.98 xx:xx:xx:xx:xx:22 active 2024/04/30 20:24:59 2024/05/01 20:24:59 23:59:34 IOT10 xxxxx local
Post reboot diff from 1.4 into 1.5-rolling-202404290019 including what vyos removed and the manually deleted listen-address:
# compare commands 1
delete service dhcp-server host-decl-name
delete service dhcp-server listen-address 'xxx.xxx.100.254'
delete service dhcp-server listen-address 'xxx.xxx.88.254'
delete service dhcp-server listen-address 'xxx.xxx.16.254'
delete service dhcp-server listen-address 'xxx.xxx.15.254'
delete service dhcp-server shared-network-name LAN1 subnet xxx-xxx.88.0/24 static-mapping xxxx-xxxxx static-mapping-parameters 'option domain-name-servers xxx-xxx.15.9;'
delete service dhcp-server shared-network-name LAN1 subnet xxx-xxx.88.0/24 static-mapping xxxx-xx-xxxxxxxxxxxx static-mapping-parameters 'option domain-name-servers xxx-xxx.15.9;'
delete service dhcp-server shared-network-name LAN1 subnet xxx-xxx.88.0/24 static-mapping xxxx-xxxxx static-mapping-parameters 'option domain-name-servers xxx-xxx.15.9;'
Resulting config in full:
set service dhcp-server hostfile-update
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 option default-router 'xxx.xxx.15.1'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 option domain-name xxxxxx
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 option name-server 'xxx.xxx.15.9'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 option ntp-server 'xxx.xxx.15.2'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 range 0 start 'xxx.xxx.15.32'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 range 0 stop 'xxx.xxx.15.47'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 range 1 start 'xxx.xxx.15.160'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 range 1 stop 'xxx.xxx.15.191'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.15.0/24 subnet-id '1'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 option default-router 'xxx.xxx.16.1'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 option domain-name xxxxxx
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 option name-server 'xxx.xxx.15.9'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 option ntp-server 'xxx.xxx.15.2'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 range 0 start 'xxx.xxx.16.32'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 range 0 stop 'xxx.xxx.16.47'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 range 1 start 'xxx.xxx.16.160'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 range 1 stop 'xxx.xxx.16.191'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.16.127'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:33'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.16.0/24 subnet-id '2'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 option default-router 'xxx.xxx.100.1'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 option domain-name xxxxxx
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 option name-server 'xxx.xxx.15.8'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 option ntp-server 'xxx.xxx.15.2'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 range 0 start 'xxx.xxx.100.32'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 range 0 stop 'xxx.xxx.100.47'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 range 1 start 'xxx.xxx.100.160'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 range 1 stop 'xxx.xxx.100.191'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.48'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:4e'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.96'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:89'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.64'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:20'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.101'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:81'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.147'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:85'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.151'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:75'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.131'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:b8'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.152'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:fa'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.129'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:60'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.155'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:5e'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.153'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:78'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.99'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:df'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.130'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:ee'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.128'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:53'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.104'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:6f'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.103'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:53'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.75'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:37'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.97'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:aa'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.14'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:b9'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.102'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:77'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.139'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:58'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.203'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:f4'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.204'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:b3'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.98'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:22'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.78'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:1f'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.145'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:11'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.100.146'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:5f'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.100.0/24 subnet-id '3'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 option default-router 'xxx.xxx.88.1'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 option domain-name xxxxxx
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 option name-server 'xxx.xxx.15.8'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 option ntp-server 'xxx.xxx.15.2'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 range 0 start 'xxx.xxx.88.32'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 range 0 stop 'xxx.xxx.88.47'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 range 1 start 'xxx.xxx.88.160'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 range 1 stop 'xxx.xxx.88.191'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.50'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:d7'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.48'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:ab'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.49'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:75'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.198'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:e8'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.56'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:09'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.68'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:a0'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.73'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:be'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.72'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:b8'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.69'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:c6'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.133'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:ef'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.74'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:68'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.83'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:5b'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.88'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:95'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.126'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:e1'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.96'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:31'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.57'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:5e'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.82'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:58'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.146'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:97'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.197'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:73'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.147'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:22'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx ip-address 'xxx.xxx.88.81'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 static-mapping xxxxxx mac 'xx:xx:xx:xx:xx:8f'
set service dhcp-server shared-network-name xxxxxx subnet xxx.xxx.88.0/24 subnet-id '4'
Boot version for reference:
$ show version
Version: VyOS 1.5-rolling-202404290019
Release train: current
Built by: autobuild@vyos.net
Built on: Mon 29 Apr 2024 02:46 UTC
Build UUID: 10b95315-2770-4705-aea6-d159b78910a8
Build commit ID: 471ac04b050b24
Architecture: x86_64
Boot via: installed image
System type: KVM guest
Hardware vendor: QEMU
Hardware model: Standard PC (i440FX + PIIX, 1996)
Hardware S/N:
Hardware UUID: 416be707-c765-4848-8fc9-4beb4df6eb36
Copyright: VyOS maintainers and contributors