Bob_C

It improved the situation but not entirely. Coincidentally I booted to my baremetal W11 on NVMe and although I had no previous issues using the Kodak Webcam, in this instance I opened Teams and the Mic disappeared for a moment (Mic disconnected message) and then reappeared a few moments later on its own. Beginning to suspect it may be a webcam quirk and although a baremetal W11 might be able to cope with it, even with udev rules, it looks like perhaps QEMU struggles with it in passthrough.

For now I have resorted to using a Ugreen USB audio adapter and connecting a wireless mic on the 3.5mm jack. That appears to work well on the same backplate connection.

So it does look more like a hardware issue with the vid and audio devices being in the same unit and not quite keeping it together.

[SOLVED]
I managed in the end to resolve all the issues.

TLDR: Had to fully remove the old Wireguard Tunnel by (a) deleing the tunnel in /Settings/VPN Manager, then (b) delete an empty <peers> folder sat under /boot/config/wireguard. A reboot then seemed to allow all dockers to be accessed as normal (using the bridge network).