"Unable to communicate with apple watch" when trying to set up unlock with apple watch

Hi,

I just got my iPhone 13 Pro Max today and transferred all the data from my previous iPhone X to the new phone. Everything works fine except when I was trying to set up unlock with apple watch function (the watch is series 4), it kept returning the error message saying "Unable to communicate with apple watch".

I've tried upgrading all the system software (iOS 15.0 for the phone, watchOS 8 for the watch), restarting the phone, unpair the watch and pair again, as suggested by some previous answers in the community , but none of these works. I really hope this function works since mask is mandatory at the moment.

Looking forward to any helpful advice.