Apple Radio Airplay working but My Music Airplay has "Cannot Complete Action" error

[patent10021]

Our Apple Radio works fine when selecting our Bose output in Airplay but when we switch to My Music and send to Airplay, all iOS devices get the "Cannot Complete Action" error message.

My Music works fine on desktop but not iOS devices.

Obviously the Bose and Airplay are communicating so this must be some kind of application error?

We've done the usual restarting devices etc. What do you think?

EDIT: ok so now all iOS devices have zero airplay playback. Neither radio nor My Music. Desktop is fine.

Hmmm Seems there is an Apple update currently in progress? When we open Apple Music spinning curser + "Updating Apple Music" message.

 

[patent10021]

Ahh Nevermind. Seems there was some kind of updating going on. Our devices had that updating message so maybe Apple Music had some kind of silent back-end update? Anyways all works now.