Why does multicast for cluster stop working?

Hello,

Running a pair VyOS 1.1.6 appliance on Citrix Xenserver 6.5.

Trying to get Cluster working (which worked for me previously on Vyatta)

If I reboot the appliances, cluster works for about 4 minutes. After 260 seconds of up time, both VMs stop receiving multicast packets from the other, so they both try to take over the resources causing an ip conflict.

I found that 260 seconds is a common IGMP timer… this is how long to wait for an IGMP report from the OS before removing it from the multi-cast group (assumes the host has left).

So shouldn’t VyOS be sending some kind of regular IGMP report like every minute or so, so that it continues to receive multi-cast messages from other members?

How would I make that happen?