Use Zwift regularly with alternately a MacBook and appletv with companion app as bridge for HR, Kickr, etc. no problems until yesterday when it wouldn’t connect. Everything has been updated, turned off/on, disconnected and reconnected and nothing has changed! I can run zwift on the phone without companion (as i did for yesterday’s stage 5) on MacBook the bluetooth setting “use zwift companion” is greyed out. Same problem with wife’s companion app on all devices too! Not sure what else to do… BTW, connected to wahoo RGT with same setup and raced without issues last night…
Did anything with your wifi change? They need to be on the same network to connect to each other.
Thought that might be the issue after recent power outages but everything is on same network I’ve been using for zwift/RGT without problems… its a mystery… 
🕵🏻♂