Please do the following:
Open 3ds max 2020.3
Empty scene opens. Maximized Perspective view by default on my side. All good so far.
Unmaximize to Quad view. Still working in Persp view.
A single click on an ortho view (left, right, etc)
3D mouse stops working at all, no movement, it's died. Buttons are working though.
Restarting 3ds max helps though.
Dear management, can you please FIRE the one who works on 3ds max drivers?!
Please! Please! Please!

P.S. Going to check 2021 soon. Will keep you posted.