I've seen posts related to this and they end up with it being a hardware problem but I find that hard to believe since both my Play 5 and my "Theater system - Play bar, Subwoofer, and two Play 1's" stopped working at the same time.
I have a 2 Play 3's, a Connect:Amp and a Sonos One that are all working fine over wireless.
If I connect any one of the components that aren't working over wireless to a wired connection they all seem to work. Since I have a wireless bridge in my TV room, I hardwired a Play 3 into it and now my system works again. I was testing with the Play 5 and the same thing happened if I used ethernet with that I could see all the other missing components.
It does appear that the old bridge I bought with my Sonos Play 5 does not work any longer and I could accept that fact that my Play 5 needs that to work but since the much newer Play bar has the same issue, I don't think that's the problem.
Any thoughts on what the issue might be?