Hi @EuroEager2008 ,
What's the version of your Outlook 365? (File > Office Account > About Outlook). Please make sure you have upgraded your Outlook to the latest version.
According to your description, I notice that you can't add your Outlook.com account as POP/IMAP account in Outlook 365. Based on my test in Outlook 365(version is as shown in the below figure), I can configure Outlook.com account as POP and IMAP account successfully. How did you add the Outlook.com account?
How did you add the Outlook.com account? For POP, IMAP, and SMTP settings for Outlook.com and Enable mail provider settings, please refer to this official document for setting and confirmation: POP, IMAP, and SMTP settings for Outlook.com.
On the other hand, it is recommended that you do this in Mail and add a new profile in the control panel(Control Panel>Mail>Show Profiles>add) to check if there're any differences.
Hope the above help!
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