I have an old monitor with a fairly small resolution, (1400x1050). When in fullscreen, if I open the recipe book in a menu, the recipe book appears directly in front of my inventory and is only closable by clicking on an option in the book or hitting escape. This does not occur when fullscreen is off, except for when the window is maximized.

Correction:
This can be replicated by playing with the horizontal window size while not in fullscreen