Managing personal Outlook.com account settings, security, and privacy
Hello Liam,
My name is Marc, an Independent Advisor and Microsoft user like you. I am glad to assist you today.
Can you check the settings on Outlook going to File, Account Settings, click on the email account, More Settings, Security Tab, make sure the "Always prompt for logon credentials" is disabled.
On credential manager, please ensure that all Outlook/email related entries are removed under the Windows Credentials. When first logging into Outlook then, please ensure to uncheck the "Remember my credentials".
Another way to resolve this issue is by creating a new profile for Outlook. You can do so by following the instructions below.
https://support.microsoft.com/en-us/office/over...
Let me know if this information helps. Please feel free to reach out if you have further questions or concerns.
Regards,
Marc