@Vectorline
I have been having the same problem with 2FA codes from my EE account.
It turned out that the original BT account had a hidden embedded (and very ancient) "mobile lookalike" Broadband Telephone service number embedded in it - not one that I could see and maintain on the account - that it somehow managed to use.
Actually a bit more obscure than that in that some devices worked to send 2FA codes and some didn't - until they all didn't.
You may want to check, if you have not already done so, that the Go Pro related number data is what you are expecting. If it is, perhaps check that it is not being intercepted and refused on the grounds of Spam or some other nefarious wide area problem. (Whether a genuine problem or not...)
