[PROBLEM] System freezes after a while

[Nutul]

PSU is not in cause... The bug is still present after last update.

Mmm, weird.

I last play some music on my Pi4 (which runs out of a 4GB Samsung uSD) almost every day from 8/9am till 7/8pm, this makes roughly 12 hours idle, and it is up since 3 weeks ago. Do you use bluetooth a lot, for instance?
I'd try to isolate the connections, first, to rule out something basic; like play local files, and on a wired connection, without any BT / WLAN etc. etc.

Cheers, Al.