JabRef 5.0-beta.419--2020-02-12--3859620
Linux 5.4.19-050419-generic amd64
Java 13.0.2

• [X ] I have tested the latest development version from http://builds.jabref.org/master/ and the problem persists

Steps to reproduce the behavior:

1. In Ubuntu 19.10 using my external display (my primary monitor next to my laptop), I open JabRef.
2. Open the menu and the list items will be displayed with a more or less significant disalignment (see jabref-screenshot1).
3. Moreover, context menus (e.g. for switching to titlecase) are located on the wrong screen, see jabref-screenshot2 where the menu hides behind the bottom of the left bar of the gnome desktop).

This issue makes it difficult to click menu items because sometimes menus close before the mouse pointer reaches them.