Teams Add in not installing with new Microsoft Teams app

Question

hi Guys

i have a strange problem. teams add in for outlook keeps dissapearing. its not showing in outlook add ins but it's showing in control panel. i have tried many solutions but nothing work.

one day maybe user turns on device and add in is there, the another day its not there. so its unstable and bothering.

Problem is after new teams and old Outlook. (with new outlook app there is no problem)

Maybe you have a final and working solution how can i fix it

Thanks