Tenant Migration and Microsoft Chat Old Threads/Files

[ifnot2]

My company recently migrated from one tenant to another. Unfortunately I am not able to open old chat threads/files since before the migration. When I search I can see that the thread exists but when I click on the thread in question, I can't open it to view the entire thread. I'm on a Mac too.

I have deleted my Microsoft Teams cache and uninstalled and reinstalled the Microsoft Team's app. But still nothing. All I can see is a preview of what I need to get to and that's it. 

How can I get to these old threads? To me it seems like they should be available but so far I don't have a solution to this problem. 

Thank you. 

[#2]

Hi, I recommend that you reach out to your IT people working with the migration as they most likely have used third-party software for this. Chats for example are actually processed and stored in Azure and only ingested into Exchange for compliance/eDiscovery reasons.

[#3]

Thank you for the suggestion. I have been in contact with them but unfortunately they seem stumped.

I’ll ask them what third party they used. The migration was completed last month but we keep finding “bugs,” for a lack of a better word.