Not sure how but the latest update (was away for a couple of weeks) has made my Sub and two Play:3 surrounds vanish. I can see that one of the Play:3s shows up on the network briefly (on 5GHz), then goes away. They are really not there - router says they are offline, SSDP fails for them. (The Sub and the P3s are bound to different Playbars).
Things are getting pretty bad when even the Desktop app can’t find them (and also my app and any UPnP utility as well).
I’m going to break out a long Ethernet cable for additional testing next. If that fails I guess I’ll reset them, but that just seems so very unnecessary.