Apple has promised to fix an iPhone 13 bug that prevents owners from using Unlock with Apple Watch. In the meantime, users can disable the feature to prevent an “Unable to Communicate with Apple Watch” error from appearing.
Unlock with Apple Watch was first introduced last April with iOS 14.5, giving iPhone users with Face ID the ability to easily unlock their devices while wearing a mask, which prevents facial recognition from working.
Update Sept. 28: iOS 15.1 beta 2 includes a fix for this problem. However, it’s not known when iOS 15.1 will be released to the public.