Two openvpn links can not load balance

my vyos version is V1.3.2.
I have two VPN links and configured load balancing for openVPN, but only one link will have data in the actual test. If you close the physical port of a link with data, you cannot switch to another VPN link. The VPN configuration of the primary link must be deleted before switching. What is the problem?

my configure:

set load-balancing wan interface-health vtun1111 failure-count ‘3’
set load-balancing wan interface-health vtun1111 nexthop ‘10.100.100.1’
set load-balancing wan interface-health vtun1111 success-count ‘1’
set load-balancing wan interface-health vtun1111 test 10 resp-time ‘5’
set load-balancing wan interface-health vtun1111 test 10 target ‘33.33.33.33’
set load-balancing wan interface-health vtun1111 test 10 ttl-limit ‘1’
set load-balancing wan interface-health vtun1111 test 10 type ‘ping’

set load-balancing wan interface-health vtun2222 failure-count ‘4’
set load-balancing wan interface-health vtun2222 nexthop ‘10.100.110.1’
set load-balancing wan interface-health vtun2222 success-count ‘1’
set load-balancing wan interface-health vtun2222 test 10 resp-time ‘5’
set load-balancing wan interface-health vtun2222 test 10 target ‘33.33.33.33’
set load-balancing wan interface-health vtun2222 test 10 ttl-limit ‘1’
set load-balancing wan interface-health vtun2222 test 10 type ‘ping’

set load-balancing wan rule 10 inbound-interface ‘eth3’
set load-balancing wan rule 10 interface vtun1111 weight ‘2’
set load-balancing wan rule 10 interface vtun2222 weight ‘1’
set load-balancing wan rule 10 per-packet-balancing
set load-balancing wan rule 10 protocol ‘all’