Finally resolved my issues without giving up and selling them!

Decades-long Sonos aficionado here.

100% of the issues (for me) went away when I wiped my entire local install—which included a PlayBar and 2 Play:1s—and only reconnected my 2 Roams, & Arc Ultra with 100 surrounds & Sub 4.

Before I deleted the entire system from LAN, I noticed that the sonosnet grid was still trying to contact a half dozen speakers I retired years ago.

Full reset and only current devices fixed it instantly. Been solid now since early October. Sucks to lose my upstairs audio but I’d rather have a working system. It is what it is.

My $0.02. Hope it helps Someone.