Yea that is because anything Realtek is an utterly brain-dead piece of crap and "quirks", and that on Windows. On Linux it's even more pain, mostly because OEMs don't bother to release the specific quirks their specialized Windows driver fork had applied. Don't even want to know how many Windows systems ship with outdated, possibly insecure Realtek drivers because the OEM long since stopped backporting fixes.

I appreciate that Realtek can be an issue, but on a few PCs they works solidly with Alsa so seems unlikely it's the kernel driver (restarting pulseaudio would bring it back, at least for a while). So it seems to me the issues are very much with Pulseaudio (rather than with the kernel).

Alternatively, Pulseaudio could be exercising different code paths in Realtek's firmware that Alsa doesn't trigger. With Realtek, all bets are open...