I'm having similar problems. Multiple clients have told me that

a) Intuit Link tells them they're using the wrong email address, although they are not. They have only one email address each and it has not changed. and

b) When they try to log into their Intuit Link account they get a message saying they have to be invited by an accountant.  Which they were.  I sent them the invitation.

These problems have become a huge time-suck for me at a bad time!  How is Intuit going to fix this?  And what can I do in the meantime? 

Thank you!