No, I’m not. Both my Mac and iOS devices are connecting as normal.

My suspicion is you’ve got some sort of wifi interference issue going on, which is causing these symptoms. 

To be clear the Sonos apps use the same network APIs as every other app out there. it is highly unlikely that any app update would cause Sonos devices to mysteriously vanish due to anything the app is doing or not doing.

However it is quite possible that the act of updating an app will cause poor quality routers to mess with the network traffic in such a way as to cause the Sonos app to fail to find them in a timely fashion.

Sonos requires routers to be a lot more functional than simple web browsing/youtube use that most home routers are designed for, and sadly many are deficient in this area. A router reboot will make many crappy routers start behaving again, for a while anyway.

I have a brand new Netgear WIFI 6 Orbi configuration with 1 Satellite.  I doubt it’s the WIFI hardware that is an issue here, I have amazing throughput on everything else I do here.  I am the only person that uses this network, too.

Throughput counts almost for nothing. What is critical for Sonos to work correctly is inter-device communications, and actually conforming to the correct standards for network packets.

The Orbi gets a special mention here, so you should carefully follow this advise:

The issues I’ve experienced are intermittent, but annoying and it is generally with the iOS application, which I have running on an iPhone 12 Pro with up-to-date firmware.

The documents above suggest altering the functionality of my (new) router to the possibly detriment to other usage, which I’m not inclined to do.   I have both 2.4 and 5 ghz bands enabled.