I have spoken about My CRA before, it allows access to your CRA account. The error I received (Error – ERR.021) was shocking. I am now locked out from this with the following screen:

The access I used was using my Banking Access (i.e. my bank card log in credentials). I have not applied for CERB (as background).
I managed to call the CRA, and was told that someone would call me back about the ERR.021 issue. This would allow me to get access to my account. I was attempting to see what my RRSP room was (as background).
Then I received the following email to the email address I have on file with the CRA.

So now, I cannot log into my CRA account, and I cannot receive emails either. I will receive something using Canada Post, explaining what is going on, and how to fix this issue.
The CBC has posted the following:
Christopher Doody, a CRA media relations representative, said in an email it was meant “as a security precaution in the context of ongoing investigative work, and is not due to a cyber security breach of CRA systems.” He said affected users can expect a letter in the mail with instructions on how to unlock their account.
CRA locks online accounts amid investigation, leaving users worried – CBC
Current Status
Still locked out of my CRA account. Conjecture is that my log in credentials were being sold on the Dark Web. (Feb 17th)
The CRA answered my tweet, with the following:
Hi there! We will work with impacted individuals to re-establish their credentials and unlock their accounts. (1/3)
— Canada Revenue Agency (@CanRevAgency) February 22, 2021
I have also a same error Err.021. Still Waiting to pickup my call its now 2 Hours and no response. Me my wife and my business all have same error showing.