Hello Rob,
Try to use your mobile and connect to the internet via mobile data not wifi and use any browser to open outlook online and try to login to that account you are facing the issue with, it will work and ask you to enable multi factor authentication MFA, after you enable it you can relogin on your laptop or whichever pc you saw the error on before while logging in, it will work.
I can confirm this worked and resolved this issue on 06/27/23 2pm EST.