Cursor disappearing (Ubuntu)

4.1EA2 Text cursor goes missing in SQL Worksheet

My cursor has changed to this blinking dot, very annoying since it is easy to misjudge whether this is the top or bottom part of the normal text cursor, therefore I often type in the wrong line.

This issue has happened to me multiple times already, resizing the window like described in the archived thread above does not fix the problem. I am running Ubuntu 15.10. Is there a way to fix it without restarting the SQL Developer?