USB C dock audio missing in last few builds

[Ian Cunningham]

Iin last few builds my USB C dock's audio has gone missing - the dock has an audio jack which previously appeared as USB sound. It could be the dock has failed but previous upgrades would wipe out my Realtek audio in the laptop and I had to reinstall that regularly.so I am suspicious of Windows 11(beta).
I notice that the Realtek survived the last few installations but the USB sound is gone.

Any suggestions. I've tried obvious things like unplugging and plugging and scanning from device manager.

[#2]

You mentioned using beta meaning you are running insider build and as you know this build is under testing. In this case, I advise you to report this issue using the Feedback Hub app.
If you know which update causing this issue, just for test try to uninstall it and see if that fix the issue?