Unable to login to Apple ID, iCloud or AppStore on Mac after updating to Big Sur

I recently updated to Big Sur (11.6.2) and have been unable to sign into my iCloud or Appstore on my Mac.

When I go to System Preferences -> Sign in, my log in doesn't exactly fail, it just loops me back to the beginning and asks me to enter my Apple ID and password again. No error message.

My Apple ID still works on my phone, and I have confirmed the login/password I am using is correct. I can also sign in at apple.com and at icloud.com.

I was successful at creating a new user via System Preferences - > Users & Groups, then logging into my Apple ID, iCloud and the Appstore that way. However, everything I use is under my primary user.

Not sure what to do here. Is there a way to get my Apple ID working as my primary user? Or is there a way to merge my two users and make the newly created user the primary user?

If anyone has any ideas, I would appreciate some help. Thank you.