Apple Watch Siri not working - greyed out

Siri settings are enabled but greyed out on apple watch settings. I can turn the settings on and off on the watch app but it doesn't make a difference.

I have tried restarting, wiping, updating, relinking, turning settings off and on etc etc etc.

What's really interesting is that I borrowed an apple watch from a friend and the same thing happened to that one so it must be a setting I have somewhere.

Please help