We are seeing exactly the same behaviour. With Perfmon running outlook.exe is writing to a db file in %temp% continuously causing disk utilisation by Outlook to be around 75% - 100%. If I turn off the Teams add-in in Outlook then disk utilisation drops to around 0.1%. This is causing major impact to users.
I have also some constant activity on my HDD. With the help of JockMullin and every suggestion on this post I used ProcMon and found the culprit that is making the constant activity on my HDD. Here is the repetative sequence: ht tp://img19.imageshac k.us/img19 /9168/acti vityqz.jpg