VIF and IGMP does not work in 1.3.x anymore

Hi I am running now for a longer time several VyOS 1.2.8 instances to connect sites and distribute multicast traffic. Here is a section of my network-plan.


last week I used add system image to test out the latest version of 1.3.6. after the migration to that version (telling the system to migrate config and keys) no multicast was delivered anymore (from MC-Send1 to MC-Receive1 and 2 - on left-router side). Beside the update of the right-router to 1.3.6 nothing else was changed.
Here are some IGMP and PIM infos from the router, when MC-Send1 was transmitting multicast:

vyos@RR:~$ sh ip igmp sources
Interface        Address         Group           Source          Timer Fwd Uptime
eth0.94          10.10.94.1     239.255.95.21   *               03:56   N 00:05:20

vyos@RR:~$ sh ip pim rpf
RPF Cache Refresh Delay:    50 msecs
RPF Cache Refresh Timer:    0 msecs
RPF Cache Refresh Requests: 1
RPF Cache Refresh Events:   1
RPF Cache Refresh Last:     44258:11:
Nexthop Lookups:            4
Nexthop Lookups Avoided:    0

Source          Group           RpfIface         RpfAddress      RibNextHop      Metric Pref
10.10.95.10     239.255.95.21   eth0.95          0.0.0.0         10.10.95.10          0    0

vyos@R:~$ sh ip pim state
Codes: J -> Pim Join, I -> IGMP Report, S -> Source, * -> Inherited from (*,G), V -> VxLAN, M -> Muted
Active Source           Group            RPT  IIF               OIL
0      *                239.255.95.21    y    <iif?>
1      10.10.95.10      239.255.95.21    n    eth0.95

I tried also other versions of 1.3 - like 1.3.2, 1.3.3 and 1.3.5 - but the results were always the same. Returning to 1.2.8 again it works as expected.
Here is the section of my config of the vifs on the right-router

   ethernet eth0 {
        address "192.168.200.70/24"
        description "MGNT-Net"
        duplex "auto"
        hw-id "00:01:2e:82:88:65"
        speed "auto"
        vif 94 {
            address "10.10.94.1/24"
            description "V94-Net"
            mac "00:01:2e:82:94:65"
        }
        vif 95 {
            address "10.10.95.1/24"
            description "V95-Net"
            mac "00:01:2e:82:95:65"
        }

I suspected that maybe the VIFs were the issue, so I installed VyOS 1.3.6 on a sophos box with 4 dedicated interface and placed vlan 95 and 94 on separate interface and guess what it work again and multicast was delivered from mc-send1 to mc-receive1 and 2 (also across the ipsec-gre-tunnel).
So I pretty sure that there is something wrong with the VIF interface.
Most of my boxes do only have two ethernet interfaces and i am heavily dependend on that virtual interfaces are working. Is there any known bug in 1.3.x for that?
kind regards
martin

here a quick addition - the network plan after the change from vifs to single ifs.