OneNote will not login

Question

I cannot sign into OneNote on either personal or SSO account on iPad app. Passkey login fails. Password login fails. iPadOS and OneNote app at latest GA versions. Deleted app, rebooted, and reinstalled app to no help.

Answer 1

First, close OneNote completely, then go to iPad Settings > Apps > OneNote > Reset OneNote > Delete Login Credentials

Enable that option, force-close OneNote again, reopen it, and try signing in. Do not enable Delete All Notebooks if you may have notes that have not synchronized. Microsoft documents this credential-reset procedure here:
https://support.microsoft.com/en-us/onenote/reset-microsoft-onenote-between-users-on-a-shared-ipad-or-iphone

Also test both accounts in a Safari private tab at OneNote on the web.

If the problem continues, could you please provide the exact error message or code displayed after the login attempt? This will help determine whether it is related to OneNote or the authentication service.