
If Teams is showing in the tray as an active app (like it does on my KDE desktop), you should be able to right-click on the icon and select "Quit" and the application will stop running. Also, in the "Settings" menu, in the Application section, there's a checkbox for "On close, keep the application running" which I believe is on by default. If you want it to completely stop when you close the window, uncheck that option. Not sure if you need to restart Teams after that change...