Apple Watch keeps resetting itself when trying to log in

Hi, I set up an Apple Watch successfully to my iPhone yesterday. Today l did a reset on my iPhone and used a backup that predated yesterday so my phone set up did not form part of the back-up. When l tried to set up my watch it appeared the only way l could do this was to erase all settings from the Apple Watch which l did successfully using the code set up on the phone.

Now l am attempting to repair the watch to the phone and l cannot get them to pair. I can go through various combinations of setting up and getting so far. I have performed many many resets of the Apple Watch. Through these previous combinations l think l did an update.

The latest l have got to is:

Pair watch via image

App says that the phone OS needs updating. When click to update app says that watch is up to date. The only way l can get past this point is to choose do update later.

Get to choose which wrist the watch will be worn on, terms and conditions, set a code on the watch cycle through the options for sleep etc

Get to the option to link account....

By this point the watch has returned back to it is wanting to pair state.

I have been through this process now at least 15 times. I have reset Bluetooth. I can't see what else l can do....