New to me Apple Watch Series 3 failing to setup with iPhone X iOS 16.7.10

Trying to setup this new to me watch but it isn't working. I have tried resetting by holding both buttons until it restarts and the apple logo appears, then holding the side button until it prompts to reset, it then has this swirly 6 circle thing that takes awhile and changes to an apple logo with a circle of hash marks that fills up, after which it is ready to pair again. Trying to pair but after selecting which wrist the phone says it is setting it up for a brief moment then unpairs. I've tried a restore as well and it is the same thing, it just fails when pairing and setting up. I've tried with an SE iOS 18 as well and the same thing. I have not paired this watch with anything so there is no UI on the watch I can navigate aside from what you get when you press buttons, and it isn't under Find my. I've been at this for days because the restore or erase/reset take hours to complete....