User cannot be @mentioned in Shared Channel, how can I enable the tagging for that specific user?

Question

Specific Users cannot be mentioned by other users in the Shared Channel. They are just not tagable, they are in the team, they are also in the AAD group visible of the team containing the shared channel, also they are visible in the Teams Admin interface under the channel, but there is no chance to tag them. Are there any ideas what I can do so the person is again tagable?
I already removed them and added them back, no change at all.

Answer 1

Dear Akko_2025

Good morning! Thank you for posting to the Microsoft community. We will be happy to help you.

It's unusual for a user to be untaggable in a shared channel, even if they meet the visibility criteria. This issue might be related to specific permissions or a temporary glitch in Teams.

1. Have you checked to ensure the user has the necessary permissions in the team? Verify that the user has access to the specific shared channel. They should be a member or guest. Double-check that the AAD group associated with the shared channel has the correct permissions and includes the user.
2. Ask the user to clear their Teams cache and restart the app. This can sometimes resolve temporary glitches.
3. Have you checked to ensure there are no ongoing service outages or known issues with Teams on your end? Check the Microsoft 365 admin center or the Teams status page at https://admin.microsoft.com/Adminportal/Home?#/healthoverview for any alerts.

Additional Tips:

• Try mentioning the user in a different channel to see if the issue is specific to the shared channel.
• Ensure the user's profile is synchronized correctly between Azure AD and Teams.
• Make sure the user is using the latest version of the Teams client.

If the above solutions don't work, consider contacting Microsoft support for further assistance. They can investigate the issue more deeply and provide specific troubleshooting steps. You can contact Microsoft support through the Teams help center or the Office 365 admin portal by going to Office 365 Admin Center (Admin permission is needed) > Support > New Service Request. The support engineers there have the correct escalation channel, and this is the most efficient way to report such issue. You can refer to Get support - Microsoft 365 admin | Microsoft Learn.

Let me know if you need any further help or if there's anything else I can do for you. Please understand that our initial response does not always resolve the issue immediately. However, with your help and more detailed information, we can find a solution together. Thank you for your help.