> One question about the flickering - when it does happen if you then switch to split view to get rid of it, does it ever happen again within that same session like if you open the same file up again using File > Open this time instead of double-clicking it in Explorer?

It never happens again in same session after you get rid of it by clicking split view.

It only happens when these two conditions are met together;

1) double click open a file "which was saved not in split viewport"
2) MoI window is not maximized.

This is probably why only few people experienced it.

More specifically;

It does not happen if "MoI window is maximized or fullscreen" and "you double click to open the file"
It does not happen if "MoI window is maximized or fullscreen" and "you open the file through file/open"
It does not happen if "MoI window is NOT maximized or fullscreen" and "you open the file through file/open"
It happens if "MoI window is NOT maximized or fullscreen" and "you double click to open the file"