I just set up my new Omada network and most things are working great.  However, I can't get Chromecast to work across VLANs.

Here's my setup:

- ER707-M2 Router

- SG3210X-M2 Switch

- EAP670 v2 Access Point

- Omada Software Controller

VLAN 1: Sony TV, Home Automation Server

VLAN 2: Phone, Chromecast Audio (x4)

Intra-VLAN casting works.  My phone can cast to the Chromecast Audios just fine.  My server can cast to the TV just fine.
But inter-VLAN casting fails.  My phone can't cast to the TV, and my server can't cast to the Chromcast Audios.

I seem to be part of the way there.  I created a Bonjour service with service ID _googlecast._tcp.local.  I then created an mDNS Rule with VLANs 1 and 2 as the service and client networks.  With the mDNS rule enabled, all devices are in fact discovered.  My phone does see the TV, and my server does see the Chromecast Audios.  If I try to actually cast, however, from my phone to the TV, or from my server to the Chromecast Audios, the connection fails.

There are no rules restricting VLANs 1 and 2, so they should be freely communicating with each other.  I even tried creating a Permit All rule between the two, but that didn't help.  My switch ports are configured to accept traffic from all VLANs.

Is there something I'm missing here?  Has anyone else gotten casting across VLANs to work reliably?  Do I have just need to try monitoring network packets to see what's failing?  I've tried searching across the forum and elsewhere.  Many older posts are from before mDNS Repeater functionality was available.  More recent posts seem to show it working for some.