Additional features, settings, or issues not covered by specific Microsoft Teams categories
Dear damonbot,
Good day! Thank you for posting to Microsoft Community. We are happy to assist you.
I'm sorry to hear that you're having trouble registering the new Teams as the chat app for Microsoft 365. To understand the issue and provide possible solution, we need more details from you, please kindly provide us the following information. Thanks in advance!
- What Outlook version are you using? See What version of Outlook do I have? - Microsoft Support.
- May I please know if this option was working with the classic Teams app?
- May I please know if you can join Teams meeting from Outlook? if you haven't check it yet, kindly open one meeting invite in Outlook and click on join Meeting link.
- May I please confirm if you sign into Outlook and Teams with the same email account? if yes, please kindly open Outlook and Teams simultaneously and click on the contact's name. Then, check if there is any difference.
In the meantime, you can try to uninstall and re-install teams and check if the issue persists.
I look forward to your update. Kindly note that the above requested information is required for further analysis and troubleshooting of your situation. Your patience and cooperation are much appreciated.
Thank you for your precious time. Have a nice day.
Sincerely,
Libeamlak | Microsoft Community Moderator