It's a known bug. I don't want to take the effort of digging it up, but there was a reddit thread about a month ago about this and someone linked to the steam forum post with tons of people having this issue and valve stating that they're working on a software fix.

Mine also does this. It's very annoying and sometimes I just plug in headphones while docked because of it. Other times I come out of sleep (specifically in persona 5) and the audio is weird and choppy, but I don't know if that's related.

Does audio work fine undocked? Before looking at something like an rma I’d recommend switching is branches to force an update and/or reimaging the ssd to see if it’s an OS issue. Idk how likely that is but beats going without the deck while it’s out for service

It's a hardware issue with the dock. Not a whole lot you can do about it

IIRC it's a bug not specific to the Steam Deck, but something to do with the way Linux is handling audio. So the fix then is harder to get implemented since it isn't confined to code that Valve controls. Valve has to wait for the problem to be fixed in the greater Linuxosphere first, but I'm sure they're assisting with it.

I've noticed that my audio only cuts out and sounds crackly with some TVs. For some reason, changing the resolution seems to fix the issue (at least for as long as I have my Steam Deck plugged in). This is with both the official dock and a cheap Anker dock.

I've never had a problem, I use a usbc dock and the audio goes over hdmi.

You may have a bad cable. Digital stuff that's got intermittent problems is often a cable issue.