I have seen a similar case on other computers but never been able to pinpoint why.
Yesterday, a translator 7.5 on Windows 10 build 1709 had his Windows in Unstacked arrangement, but the main Paratext window was not maximized.
-I maximized the main Paratext window
-I moved/resized his existing windows (not have the Footnotes Pane showing), but did not create a new text combination.
-I closed and reopened Paratext
-All of his windows had the Footnotes Pane showing and taking up about 90% of each project/resources window.
I guess I should have sent a Problem Report, but I didn’t think about it. I’ll see if he is still around.
SIL+LSS+PNG