Perhaps try moving the speaker nearer to the local router and see if that maybe resolves the issue.

Exactly same probablem here, only era 100 with the problem, move, roam, beam and symfonisk working well. 
Sonos technical Support does not find a Solution. 
I am totally sure is a firmaware issue of the era 100 related to airplay 1. Airplay from iPhone or iPad works ok (Airplay 2). 
Last firmware update around a month ago.

really disappointed. 

Maybe see these links & requirements for AirPlay 2 …

https://support.sonos.com/en-us/article/stream-airplay-audio-to-sonos

https://support.apple.com/en-gb/101611

Edit: Note in the first link shown above, it mentions… "You can also use AirPlay 1 to stream system audio from macOS to Sonos, but you may experience a delay, or audio interruptions”.

Airplay 1 has works perfectly good for years…today still is working in all my Sonos speakers except Era 100…

I’m sorry I can’t really add anything further, as I usually just AirPlay from an iPhone, or iPad, and that seems to be working okay. What App/source-device are you using?

iTunes running on a win 11 machine. 
Raspberry pi 5 running LMS (lyrion music server)

Airplay 2 from iPhone or iPad or macOS works ok. 
 

With airplay 1 the Sonos app shows the Era playing, but no sound is produced. 
 

thanks 

This is exactly my problem.  I have a massive library on my computer so I have always used iTunes to airplay.  Stopped working on Era 100’s, but my roams work just fine.  I even tried moving to the windows “apple music” app, but that didn’t work either.  Over an hour on the phone with support and they couldn’t find the issue.  I can also play from my phone through airplay.

We need Sonos fix the the problem. 
I am 99% sure is a firmware issue. 

LMS Airplay Bridge plugin uses AirPlay 1/RAOP .    On newer models (ERA 100, ERA 300, Move 2, Roam 2, Arc Ultra) in a recent firmware update appears to have disabled RAOP audio.  My workaround is to play LMS to my Roam SL and then group my Move 2 to the playing Roam.  Then they both play and can adjust their volumes independently in the Sonos app.  The correct solution is for Sonos to re-enable RAOP in their newer models via a firmware update.

Good idea, I am going to test it tonight!

thanks. 

I have also tested it on my Sonos Port as the LMS player.  Whilst the Port is playing, go into the Sonos app and group the Move 2 or other new no output speaker with the Port or working equivalent that still receives Airplay 1.  Unfortunately the grouping is lost as soon as you change the LMS playlist, so you have to regroup  everytime.  Sonos undoubtedly loses a lot of customers amongst those unwilling or unable to spend hours hoping to get their products working reliably.

It is impressive the bad performance of Sonos. 
Thanks

It is working again! 
Thank you Chris1310. 
 

Hope Sonos fix the firmware soon!