Hi Richard,
Just noticed your issue… I also have a Wattbike Atom and have flagged this to Wattbike. I commented on another recent post … check it out here … https://forums.zwift.com/t/calibration-for-wattbike-atom/19614
In short it seems like its a Bluetooth communication protocol issue with the Apple TV/Wattbike/Zwift … if you have access to another device (iPhone/iPad etc.), use that for any workouts that have ‘freeride’ blocks - you can change gears/resistance then…
Hope that helps