I posted a thread of possible relevance:
Note: The title is tongue in cheek - I was the dummy in that thread. Don’t be like me. TL;DR: “Give all your devices amnesia.” Ensure they are UNPAIRED and FORGET the trainer - I mean everything - computers, smart phones, apps, E-V-E-R-Y-T-H-I-N-G. The “Nuke it from orbit - it’s the only way to be sure” solution. This includes the AppleTV Settings (not Zwift, the ATV settings) - check for the trainer in the list of bluetooth devices and remove it if it’s there.
Last resort: factory reset the AppleTV, set everything up again from scratch.