You could just group them, but there are so many different responses, I’m not sure what you’re asking anymore.
Normally speaking, you should be able to play any stream on any speaker (or room). If you can’t, I’d be tempted to do several things. First, reboot the affected speakers, along with your router. I’d also check for updates, both to the speakers and the controller on whichever device you’re using as a controller. Especially as there have been at least two updates since Sonos dealt with the ‘repeated login’ issue.
The PLAY:3 is such an old speaker, it can not be a target for either Bluetooth or AirPlay 2, it was designed and built before those electronics were able to be included.
However, if those steps don’t work, I would recommend that you submit a system diagnostic within 10 minutes of experiencing this problem, and call Sonos Support to discuss it. But don’t post the resulting diagnostic number here, they get sensitive about GDPR.
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.