The problem seems familiar to me.
Especially the first one has exact same solution as yours. Don’t know why these stuttering audio glitches appear, and whether it is being solved. Might be more apparent on low-end machines. Might be memory leakage problem on some audio services (cumulative over use time & “suspend to RAM - wake up” solves the issue). Anyways, I suspect the issue being on QubesOS’ side.