Fenix 6 sapphire won't connect to iphone anymore

I have followed all advice on removing apps, devices, turning off and on etc.  The fundamental problem is that when i select phone on the watch there are no options to pair.  It's almost as if there has been a software update on my watch and something has changed.  The watch face is now just digital numbers etc.  Is there a way I can reboot the watch rather than just turn the power off.