iPhone Storing Numbers in Odd Format

[Dick Montage]

I recently changed mobile provider, but kept the same iPhone 11 Pro Max.  Since moving, it has started messing around with phone number formats.  It's worth noting that everything is synchronised with iCloud.

 

I am in the UK and it usually stored numbers in the format 07701 234567, but now SOMETIMES it seems to present them as 07 701 23 45 67.  I don't know if this is a problem per-se, but it's certainly annoying.

 

However, when it does this, it seems that incoming calls no longer show the person's name but rather their number.  Moreover, I sometimes cannot call the person and it says incorrect number dialed.

 

I'm not sure what's going on...