Bug: Window height changes after Acrobat DC closed with the menu bar hidden.
Steps to reproduce:
Open any PDF document in the Acrobat Reader DC on Windows (my version 2021.001.20138)
Change the following (I do it for every single document, that should be the default):
View -> Page Display -> Single Page View
View -> Zoom -> Zoom to Page Level
View -> Read Mode
View -> Show/Hide -> Menu Bar
Resize the window so that the page takes up precisely 100% of the window area, there are no blank margins around the page.
Close the window
Open the same document again
Window size should be remembered. When you apply all the actions from step 2, the page will fill up precisely 100% of the window space.
Window height will be slightly larger. When you apply all the actions from step 2, some narrow blank area appears below and above the page. Each time you do that, window height grows bigger and bigger. After opening the document several times (each time hiding the menu bar) the window becomes taller than the screen!