I’ve re-faced the same problem after starting Roon on my iPad and it offering me updates being available (apparently only remote updates as I had installed all local updates before, already).
Afterwards I could no longer play music on my iPad and Roon on my MacBook always caused also Roon on the Mac Mini which supposedly runs the core to play the music, irrespective of its Audio zone settings.
Last time a reboot of all involved devices worked and I assume it will do so today, too. However, I would appreciate if there was any advice what form of logging I might be able starting prior to the update the next time it happens to narrow down the root cause.
Thanks, and best regards,
Ingo