My main screen is a Sony Bravia connected through HDMI and whenever I start anything that triggers audio output, like say a youtube video, the TV gets a signal reconfiguration telling it to enable audio. When I stop the video, the TV gets a signal telling it to disable audio. In both cases this triggers an overlay, and when enabling it takes a few seconds, meaning I miss the first few seconds of audio sent to it.
This does not happen when I'm on Windows, but it happened in Ubuntu 18, 20 with my RX 580 and now in 22 with my RX 6750. And that doesn't even touch upon the crackling that starts happening after multiple audio on and off cycles. This is a fresh installation, and everything is at its defaults (except Firefox; I had to update that myself).
You should never be telling the external device "okay, turn off the audio now" unless I've switched to using another output. If this is some setting that can be fixed by an obscurely-named setting that can't be found in documentation unless you actually know it, then it's still wrong to have this behavior as the default.
Since screencapture software won't capture the overlay from the TV itself, I had to record this demo with my phone https://www.youtube.com/watch?v=AWTfyyzSH_w