I’d try three, make that four things. First, I’d try that reboot of the speaker, even if you’ve tried it before. Wait two minutes while it is unplugged, to allow the electronics to ‘drain’ fully. While the speakers are powered down, I’d (second) reboot the router. This will ensure that the speaker will get ‘fresh’ IP addresses (although this may not be the issue, it is still a smart thing to do). Third, I’d reboot the Apple device that you’re using to try to connect via AirPlay 2. Finally, if none of that works, I would submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it.

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

As a note, I wouldn’t ever want to send two AirPlay 2 streams at the same time two two different Sonos targets, which would double the bandwidth requirement from my Apple device (for me, most usually an iPhone or iPad, but randomly, a Mac). I’d instead send one AirPlay 2 stream to a Sonos device, and then use the Sonos ‘grouping’ feature to spread that signal to all other Sonos devices. That would limit the strain on my Apple device’s radio signal.