IGMP enabled without router

I’ve got an issue pairing a Poly Studio X50 with a Poly TC8. The X50 is essentially a soundbar that sits under a TV and connects via HDMI, whereas the TC8 is a touchscreen used to control the X50. It’s a Microsoft Teams Room device solution and both devices are independantly plugged into the cnMatrix switch.

https://docs.poly.com/bundle/polypartnermode-ag-3-8-0/page/t3919548.html

The two will not communicate with each other and therefore won’t pair. I’ve worked around it for now by plugging in a non-managed switch and they pair just fine.

The devices are plugged into the same EX2052-P switch and both ports are on the same vlan.

I beleive it’s all down to the IGMP that’s enabled by default on the cnMatrix but we don’t have IGMP capable routers so the multicast packets are being dropped by the switch which means they won’t talk to each other.

How do I configure the cnMatrix switch to allow these two devices to communicate while not flooding the network with unecessary multicast traffic without having a suitable router to manage the IGMP requests?

We use XMS-C to manage all our switches which has no IGMP config options so I need to factor that in too.

Thanks for any help,
Jon.