Michael,

I can't find in release notes but there was this small bug in previous versions when you open a file which was saved in maximized view (top, front, 3d, etc,...) screen was flickering (MoI was trying to switch between split and maximized viewports every time when you move your mouse) To fix this, every time I had to change viewport back to split after I've opened those files.
Right now I can't replicate this issue any more. It seems to be disappeared in Nov-19 beta.

Thanks.