Hi kyleer1,
Appreciate you giving those steps a go. That "MYOB account has already been linked to a user in this company file" message is basically saying your my.MYOB email is already tied to an existing user ID (often Administrator or an old username), which is why you still have full access. You can double-check this by clicking through each user in the list and you’ll spot one whose email matches your my.MYOB email. For that user, just tick the box "This user will sign on with a my.MYOB account/Create an online MYOB login for this user."
If that still doesn’t do the trick, that’s our team's cue to jump in and take a look behind the scenes. There might be a setting on our end that needs a little tweak.
Cheers,
Princess