Are you trying to use a business account or something? Otherwise I have no clue.

I have both a personal and a business account, but the login is the same, and they fail at the login level, not after I'm authenticated. One cannot tell what sort of accounts are behind the account before you successfully log in.

I have no idea then, it's worked for me in the past - Plaid asks me to give them the 2FA auth code I receive via text.