I’ve had my Apple Watch for about a year. I just updated my phone to IOS 15 and in the process my phone no longer remembers my watch no clue why. And now it won’t even let me pair it. It’s saying I need to enter an Apple ID that doesn’t exist anymore. Not sure what to do because I can’t access that Apple ID.
Apple Watch Series 3, watchOS 8
If you are the ORIGINAL owner, then see the 'Start a support request' section in:
How to remove Activation Lock - Apple Support
You can ask apple to remove the activation lock online on this page;
Online Activation Lock Removal Tool.
Or this;
If you can't remember/gain access to the apple id that paired the watch to the phone.Take the watch and it's receipt along with some photo id and any other proof of ownership to an Apple Store and request that they remove the Activation Lock for you.
Apple Watch issue pairing
