same here. Called sonos support after sending my report. stayed online with them over na hour. best answer was that my wifi channel was too crowded. changed the wifi channel using the router automatic setup. nothing happened. 

I use my apple tv with a beam gen 2 and my iphone with a sonos five. no windows or other firewall to mess with that.

everything was working like a charm until last week. really disappointed. I have several sonos speakers in my place and my mothers, (beam + sub mini, five, 4 ones, 4 roams, amp) and can't keep resetting them.

not to say the trouble the roams have syncing with all the other speakers. whole lot of money and really bad support...

As I’ve said before, I frequently have to reset the Apple device sending the AirPlay 2 stream, but not the Sonos device. Even recently, with a significant amount of electrical brownouts, it hasn’t been the Sonos I have to ‘reset’, it’s been the Apple TV that needs to be reset. 

I will note, however, that after rebooting a Sonos speaker, it takes a few minutes for it to show up as an AirPlay 2 device in the Apple interface, sometimes as much as 10 minutes.  At this point, if I’m moving a Sonos speaker, by unplugging it in one location, and moving it elsewhere, I usually wait half an hour before even attempting to ‘see’ it in my iOS device’s AirPlay 2 connection interface.