
Hello SRose,
Thank you for reaching out here in the Microsoft Q&A forum.
I can understand the inconvenience this issue, where a deleted account from your Authenticator App is still recognized by the website, has caused you.
This typically occurs when the initial registration process is interrupted, causing a mismatch between the website's records and your Authenticator app.
Attempt to start the process with a fresh browser session to rule out any cached data issues: Open a new InPrivate window in Microsoft Edge or an Incognito window in Google Chrome > Paste the link from the company into this new private window and try to sign in and set up the account again.
If the private browser window does not resolve the issue, you will need to completely remove your guest account from the other organization and then re-join:
Step 1: Navigate to your Microsoft Account page: https://myaccount.microsoft.com > Sign in with the email account that received the guest invitation.
Step 2: From the menu on the left, select "Organizations" > Find the name of the company you are trying to access and click the "Leave" > Confirm
Step 3: After leaving, you must wait approximately 15-20 minutes for this change to fully synchronize across all Microsoft services.
Step 4: After the waiting period, click the original invitation link again. This will restart the setup process from the beginning and should allow you to add the account to your Authenticator app correctly.
Please let us know if these steps help.
Best Regards,
Alex | Microsoft Q&A Support Specialist