iPhone FaceTime adds +44 to US numbers in UK

I have a friend I am trying to help with an iphone who is overseas trying to facetime.

He lives in the US and his location is set to US. He is in the UK.

Every time he tries to make a facetime call its adding +44 in front of the number and trying to turn it into a UK number.

The numbers have +1 in front of them. We have tried changing his location to the UK, and changing it back to the US. We've also tried to sign out and back in.

Any suggestions?