Why is my Apple Watch stuck on the pairing screen?

I bought a new Series 9 watch in February 24 and paired it to my IPhone without difficulty. Last week it stopped pairing for no apparent reason and won’t re-pair. I have followed all the suggested routes to no avail.

the watch app is now ‘stuck’ on the pairing screen so I can’t get into it to try unpairing the watch.

i have started and restarted both devices to no avail. I’m thinking of deleting and reloading the App. Do you think that might help or cause more problems?

[Re-Titled by Moderator]