Separate VLANs: Mac Mini working, Windows not working

Morning all.

Router: UDM
Roon Ver.: Latest

VLANs
IoT: Roon Server, Smartphones & tablets, Chromecast Audios, Ultra and Nest Hubs
Computers: Laptops & desktops

My Roon Server (currently on a Server 2019 Hyper-V VM) sits on my IoT VLAN. It’s on here, primarily, as Chromecast speaker groups cannot pass over L3 routing (at least, no way that I’ve found with my router). Everything on the IoT network, with smartphones and tablets as control devices, works as expected. I also wish to use my computers as control devices as I listen to music via a USB DAC & headphones whilst working. Now, my Mac Mini works perfectly well in this regard, with all local audio devices being exposed. My Windows desktop does not: Roon doesn’t pick up any of its audio devices.

Firewall logs from my UDM router are not showing anything being dropped. Nothing, in fact, gets passed the Roon specific rules that I’ve put in place (I have an Accept All logging rule directly afterwards) when using Roon, so everything both control device or server is doing over the network is allowed by the Roon rules, asd far as I can tell. I stripped out the rules (which broke the Mac Mini) and rebuilt them based on logged traffic, but this didn’t help the Windows box (the Mac started working again).

I’ve contemplated what would be Windows specific. Both server and control firewalls are off. I’ve enabled NetBIOS to broadcast to the router (though I don’t think this is required). I’m a bit stumped for the moment.

I know it’s not supported, but given that others have it working, and my Mac works fine, maybe someone has some insights.

Thanks!

Peter.

Do you have anything else in terms of audio software installed on the Windows box

I don’t, no. I’ve also just tried it on my work laptop, connected to the same Computers VLAN. That behaves in the same way: no local audio option is presented through Roon, but all the Mac stuff is there.