My account constantly auto block 1 of my friend

Hello Dang Tran,

Welcome to the Microsoft Q&A forum.

I understand how confusing this situation can be - being unable to chat with a specific contact when the block status keeps reappearing, especially when the contact does not show up in your blocked list and the issue only affects one person.

Please be advised that, from within the Microsoft Q&A forum, there is no visibility into Microsoft Teams Free account synchronization or conversation metadata on Microsoft’s servers. The steps below therefore focus on resetting the contact and chat state using options available directly in the user interface.

1, Confirm the block status on both sides

Ask your friend to check their own Microsoft Teams Free settings to ensure you are not blocked on their side. The chat relationship depends on both accounts.

2, Remove and re‑add the contact

Sometimes the contact relationship itself needs to be refreshed.

• Open Teams Free > People > Contacts
• Remove the affected contact
• Sign out of Teams, then sign back in
• Add the contact again using their email address or phone number

3, Start a new chat instead of reopening the old one

If the previous conversation shows “This chat doesn’t exist anymore,” avoid reopening it. After re‑adding the contact, start a new chat from the contact’s profile and check whether the block message reappears.

4, Test on another device or reinstall the app

If the issue started on mobile, test from Teams on the web or desktop (or vice versa). If the behavior is identical across devices, uninstalling and reinstalling Teams Free on the affected device can help refresh local app data.

5, Confirm the scope of the issue

Check whether you can chat normally with other contacts. If only this one contact is affected and the block status keeps returning without appearing in the blocked list, the issue is likely isolated to this specific contact or chat relationship rather than your overall account settings.

I hope these steps help clarify what’s happening. Please feel free to share what you observe after trying them, and I can continue to assist.

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".    

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.