Did you also check if you can login via webmail? This is Important since it will validate if password being used is correct.
Next, you need close Outlook and every other program then you need to clear the stored credentials.
- Press Win + R
- Type: "control keymgr.dll" (do it without the "")
- Under Generic Credentials, remove everything related to:
- MicrosoftOffice
- Outlook
- ADAL
- OneAuth
- MSOID
- Restart Windows
Then you can check Outlook again.