Dragging a Maximized Window Doesn't Work
When a window is maximized, moving the cursor to the top pixel on the screen and dragging down will restore the window and allow you to drag it. In Teams, this selects all text instead.
(I'm guessing this is something with Electron but it's annoying)
Ladislav Šesták Jr. commented
I have the same issue. Here is a screenshot of this issue.