When will Sonos figure out how to push updates that don't break everything?

A big part of your problem is doing the Factory Reset, it rarely solves anything, removes needed diagnostic data and makes so much extra work. It should be considered a last resort and only done after consulting Sonos Support.

If you would like some user to user suggestions there are folks that would be willing to help.

I’ll toss out a first possible fix, it only takes a few minutes and has helped a number of folks with after-update issues.

Go to your router’s DHCP settings page, add a static/reserved IP address for each Sonos device you have. Power down all Sonos, reboot router and Controller, power up your Sonos.

See if that helps or if the problem persists ask for user help here or contact Sonos Support.

Already halfway through the factory reset (it was the only thing I’ve been able to get to work in the past).

Will try manually assigning IP addresses after that.

Let us know if that doesn’t help, someone here is sure to have a better solution than the mess Factory Resets cause.

I have a similar setup (Arc Ultra a 2x Ones) and the same problem, it very much points to the Patch on the 7th of the month.

The only luck I have had in getting it to.appear and stay in the app is to cable the Arc ultra to my network, it also now mentions that this is required for the Ones to be surrounds which it didn't previously.

Cabling the Arc isn’t an option for me. 
Sonos really should have a more rigorous QA process. I have dozens of apps update every month and none has a severe an impact as this. Surely you can do better Sonos!

So potentially the App needs an update as the advice it provides is contradictory.

There’s a difference between resetting one uncooperative speaker and resetting the whole system, but maybe this could be made more clear. 
 

The only reason I can think of for Sonos to advise you to cable connect surrounds is when you’ve accidentally turned off WiFi on the Arc - this setting also disables the direct 5Ghz link to the surrounds and Sub(s).

All updates bring with the, the need to restart al speakers, probably all at once. Routers do get confused by this. These kinds of problems after an update do point to router problems.