Messages not Coming through from a specific Colleague

Hi Felix Andrews

Welcome to Microsoft Q&A forum 

To better understand your situation, may I clarify a few more details: 

1.Is this issue happening in only one specific 1:1 chat, or are there multiple people they can’t properly send/receive from? 

2.When they open that specific chat, do they see the other person’s new messages appear eventually, but without any notification, bold chat in the list, or red badge/number? 

3.Are the sender and receivers on the same tenant/domain? 

Beside several steps you have already tried, I recommend: 

1.Clear Teams cache for both sender and receiver 

For window: 

-If Teams is still running, right-click the Teams icon on the taskbar, and then select Quit. 

-Open the Run dialog box by pressing the Windows logo key  +R. 

-In the Run dialog box, enter the following path, and then select OK 

%userprofile%\appdata\local\Packages\MSTeams_8wekyb3d8bbwe\LocalCache\Microsoft\MSTeams   

-Delete all files and folders in the directory. 

-Restart Teams. 

For macOS 

-If Teams is still running, right-click the Teams icon in the dock, and then select Quit or press Command -Q. 

-In the Finder, open the /Applications/Utilities folder, and then double-click Terminal. 

-Enter the following commands, and press Return after each command: 

rm -rf ~/Library/Group Containers/UBF8T346G9.com.microsoft.teams ``

rm -rf ~/Library/Containers/com.microsoft.teams2   

-Restart Teams. 

2.Delete the current chat and start a fresh one 

-In Teams, go to the problematic chat > click the three dots (…) at the top > Delete chat. 

-Then search for the person again and start a brand-new 1:1 chat. 

-Test in this new chat 

3.Re-install Microsoft Teams app 

-Quit Teams completely. 

-Go to Windows Settings > Apps > Microsoft Teams > Uninstall. 

-Also uninstall “Teams Machine-Wide Installer” if you see it. 

-Restart the computer. 

-Download and re-install the latest Teams 

The initial response may not fully address your needs, but it will help me better understand your situation and give the advice. Thank you for your patience while we work through it  

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The Issue happens in 1:1 chats with that person, if it is a group chat with 3rd person involved the chats go through fine. and yes they are on the same domain (in the same team) the chats dont come through at all.

i have done a repair on teams which i believe would clear the cache ? next step i was going to do was a full reinstall.

Have now done a full teams reinstall, waiting to hear if makes a difference.

Latest update is that the original affected colleague still cant see their colleagues messages, but their colleague can see theirs.