I had the same issue and this is what I did to work around it.
I turned off my firewall and also did the following actions on my Mac.
Go into System Preferences and do the following steps:
System Preferences > Sharing > Service: Screen Sharing, check the box to the left of Screen Sharing.
Make sure to verify which users can share their screen.
If you will be sharing files make sure to check the box next to > Service: File Share.
Also select Options and check Share file sand folders SMB and select the account on the Mac which will be sharing the file (you will need to enter the password for the user to allow this action).
Hopefully this helps with Mac users and utilization of Microsoft Teams.