Register teams as the chat app for office

Hi bwillocx,,

That might be a cache issue, this can be solved following this guide.

https://www.onmsft.com/how-to/how-to-clear-your-microsoft-teams-cache-on-windows-10#:~:text=1%20Quit%20Microsoft%20Teams%202%20Cut%20and%20paste,entire%20folder.%204%20Restart%20Microsoft%20Teams.%20See%20More

Should the problem persist there is a Registry solution provided by Lee Ford (MVP)

https://www.lee-ford.co.uk/change-teams-to-the-default-im-app-by-using-a-script/

I hope this helped.