Perhaps your issue is the same as this xmonad issue?
The Java gui toolkit has a hardcoded list of so-called
"non-reparenting" window managers. xmonad is not on this list (nor are
many of the newer window managers). Attempts to run Java applications
may result in `grey blobs' where windows should be, as the Java gui
code gets confused.
A solution is to export _JAVA_AWT_WM_NONREPARENTING=1.
According to https://wiki.archlinux.org/index.php/Dwm#Fixing_misbehaving_Java_applications, you can also use "wmname LG3D" to hack the window manager's name.