The previous post on this topic assumed, falsely, that the problem was only in Linux.
NOT SO.
I get the same issue in Windows 10 as well.
But importantly I ONLY get the issue with my LG TV, using HDMI audio. Using my monitor, with headphones plugged into the monitor, that works fine in Windows and Linux.
What kind of worked:
Reverting to an older driver ( 19.0.3..? maybe )
What didn’t work:
HDMI Link Assure setting in Radeon
Changing from PCIE-4 to PCIE-3 in Bios
Updating drivers
Updating TV software
Changing the HDMI cable
What completely worked:
Buying one of these things:
That’s a “Club3D DisplayPort 1.2 (Male) to HDMI 2.0 (Female) Ultra HD Active Adapter”. Plugging that into the Displayport port of my GPU, then attaching the TV’s HDMI cable to it, solved the issue completely.
I shouldn’t have had to buy this. The AMD drivers should have been better, but the choice between spending ยฃ25 and getting a working system, or shipping my GPU off for a refund or a refurb or whatever and losing access to it for a week or two….well.