Hi @apps2,
Welcome to the Auth0 Community and sorry for the delayed response!
The behavior you mentioned above where a user is constantly challenged with the Prompt for MFA page after entering valid credentials is currently expected. I understand this could be frustrating for users that would like to sign in/sign up using a different account, so at the moment I would recommend implementing this workaround - Allow Users to Navigate from the MFA Page Back to the Login Page that uses a custom logout button.
This feature request has been raised up already, so I would definitely encourage you to upvote this thread, as well as replying to it so it can get more visibility.
Thanks for posting your inquiry and I hope this helps!
Kind regards,
Remus