Self-close, time correction had not been synced in Google Auth. Leaving T168064 open

@Tgr I'll show myself out, it was a timing issue with GA. For the future, the solution is;

@TheDJ not my finest moment, as I actually was a rather outspoken advocate of 2FA being introduced and wrote the English Wikipedia guides on using it..

@Anomie for what it's worth Chrissymad uses FreeOTP as well. Thanks for clarity though, doesn't look like it's a direct issue with the 2FA functionality as there are other people I've mentioned this to who don't have issues..

As There'sNoTime's confirmed alt I can confirm the above - it appears other users have also been having issues with TOTP clients supplying invalid tokens/WP not accepting valid tokens.