Additional meeting and call-related features and issues within Microsoft Teams for business
There is a way to move the window.
You have to minimize Teams so you only see the screen video of the other person in the lower right hand side your monitor. From there, click and hold the video box and move it to wherever on the screen. Hope it works for you.
This is working only in 1:1 call. Not working when you have more than 1 participant. The participant's display pane does not move from the bottom.
Also doesn’t work when someone is sharing their screen. Which for probably most calls is quite often.