Apple Watch Series 2 Pairing Failed

Hi All

My friend has an Apple Watch Series 2 which would not update.

We reset the watch and go through the motions to pair again through the iPhone app but it keeps failing. I wondered if it was his iPhone but I have tried mine and I get the same results.

The watch shows the message to put the iPhone next to Watch

My phone detects the watch

I hold the phone up to the watch

The watch face changes to the back of the watch. The phone prompts to update the watch.

On pressing Update Now the phone starts to activate and then says Pairing Failed

After pressing Start Again the phone takes a while to unpair and after a while the watch face returns to the move phone to watch icons.

Any suggestions?

Thanks in advance.