My Apple Watch fails to pair with iPhone 15

i recently got a new phone (iphone 15) it’s all up to date i tried powering it off and back on my apple watch series 6 was paired with my old iphone 11 i unpaired my watch from the 11 and tried to pair to my 15 it’s not working..? the farthest i get is to scan that little screen then it says “unpairing apple watch this may take a minute” then it goes back to the home screen to set up apple watch??? i know the watch needs to be updated but i can’t update it without it being paired to an iphone?

[Re-Titled by Moderator]

Original Title: apple watch not pairing