To my knowledge, the PLAYBASE with the PLAY:1s should have never showed up as an AirPlay 2 target in your Apple’s software, they don’t have the hardware necessary to receive an AirPlay 2 signal. 

On the other hand, your two Ones should have, and allowed you to group them with any other Sonos room in the Sonos software, something I have frequently done in the past. 

I’m not sure I have an easy explanation as to why the pair of Ones isn’t properly showing up, but I do have a couple of guesses. Are your Mac and iPhone on the same subnet as the speakers? That may be a convoluted way to ask if you’re running a mesh network, sometimes the way they can be set up splits the network into disparate parts, and Sonos does require everything to be on the same subnet. 

Also, much less likely, I think, is if you’re running different applications when running into this? My understanding is not all apps (although likely not many these days) haven’t updated the newer AirPlay 2 SDK in their apps, and consequently can’t ‘send’ an AirPlay 2 signal. I guess that begs the question as to how you’re trying to access AirPlay 2, as well. From within an app, or from the OS directly, before you start any playback app?

Finally, and likely most importantly, have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it?