There are two common reasons why the 2FA code from your phone's authenticator app won't work.
(1) Out-of-sync Time
If you have access to your 2FA codes but are receiving an 'Invalid login' message, please update the time settings on your phone from Manual to Automatic and ensure the correct code is being used.
(2) Mixing up multiple 2FAs
We allow clients to create 2FAs for four different account functions:
If you create 2FA for more than one of these functions, please make sure they are properly labelled within your authenticator app(s) so you know which code is for what.
By default, below is how the 2FA codes will appear when scanned into Google Authenticator: