Mixer on the right

Hi,
I use the mixer a lot because I mostly only use MuseScore for playback of scores with multiple instruments. But, since I updated to MuseScore 4, it's not letting me move the mixer to the right of the screen, only to the top or to the bottom.
This is a real problem for me because I work on a laptop with a not-so-big screen resolution, so if I put the mixer at the bottom or at the top, I cannot see more than one staff, making me unable to work with more than one instrument on an efficient way.
Please, tell me how to fix the issue, this is really affecting my workflow.
Thank you.