You might want to try a reboot of everything, your speakers, your router, your iPhone. Not sure which one it is, but I’m certainly able to AirPlay 2 from my device to the compatible Sonos speakers I have. 

Must be something else. I can AirPlay from the Sonos App on my iPhone and get sound out. When starting a song from the iPhone Music App, it starts but no sound and stops after 10 seconds.

I’ll be interested to hear what Sonos support says, after your diagnostic submission and a phone call. 

Me too.

Same from Bandcamp, track starts, no sound then stops after 10 seconds. Maybe an iOS bug.

You state  “I can AirPlay from the Sonos App". The app is just a remote to the system. It does not play anything - the system does. You should not be able to Airplay from the Sonos app.

Update, better late than never.

It is working again. I assume the iOS update did the trick.

No reply from Sonos.

AirPlay issues. Called Sonos support we had to reset speaker to factory settings. AirPlay worked but next day I tried and it was not working again. Still haven’t gotten it to work. ‘AirPlay can not connect to Sonos’ error, so frustrating. I think this started happening after the last Sonos update. If anyone have any suggestions or fix please let me know. 
 

thanks. 

Just tried this from my iPad. Worked fine. This is after yesterday’s update.

Can we get more details? Which iPhone, which iOS, which Sonos speaker?

I have an iPhone 15pro with iOS 18.5. Speaker is a play 5. My wife’s phone is giving same error.