Spoke too soon. The status changed back to offline after reopening the
app about 15 minutes later. With Cloud Services off, I also can't see
and manage connected devices.
One additional point. In another thread, someone suggest disabling Nest
Cloud services. I did the, and disabled the router and point usage
stats, and the problem clears up. It's unclear to me if I can manage my
network while away, view devices, etc w...
I have 4 Google Wifi APs and have the same issue. Hard reset didn't fix.
When I turn on IPv6, all the devices show online, but turning it back
off pushes everything back to "offline" status.