Seems like I spoke too soon. After plugging it to the charger, the woosh sound got stuck on a very short (100 ms?) loop. As more sounds happened, the new sound replaced the loop, e.g. tapping the screen made the sound go cl-cl-cl-cl, and a notification popping up made it go sh-sh-sh (from the woosh).

Stopped after reboot.

System was under load and charging. Still, if that's the only issue, it's still worth it. Will keep testing.