Stop Outlook trying to format phone numbers?

[tripitaka]

I'm trying to tidy up my contacts that get synced between Outlook and my phone.

Firstly, it had an annoying habit of dropping the + from the start of international numbers.

I have been going through the contacts and putting them back in, however now if I have a contact that starts

+447738... for example, outlook inserts a space so it looks like
+44 7738...

This is incredibly annoying. How do I make it stop?

Thanks!