Register Teams As The Chat App For Office Registry. Once a user is upgraded to teams, he will be prompted to complete the setup process. Possibly a tenant wide global setting overwriting your local settings.
Where before within the office application, you pressed a button to initiate a skype chatt, teams now starts. We seemed to have success copying it locally, running as admin, then making sure the register teams as the chat app for office was set in the settings on teams. Select the below highlighted checkbox.
Restart the teams application (and view the settings to see if they had updated) # stop teams process.
Please note that teams runs in the background. Ensure register teams as the chat app for office. The settings on this page are saved automatically. General > register teams as the chat app for office;