So far I have tried different Java versions 6, 7 and 8 in combination of 32 and 64bit with different Java look and feel. I have also tried SH3D version 3.4 and 4.0, same problem. Started with Windows 7 compatibility and admin rights had no effect.

I have found already reported bug https://sourceforge.net/p/sweethome3d/bugs/684/.

Also according to this issue there is at least one another application with the same problem https://github.com/magefree/mage/issues/1514.

My current conclusion is that it have to be problem in JVM directly or on OS or graphic card driver level, because same problem was reported on Windows 7 and 10 and on nVidia and AMD graphic cards.

I think it is not related directly to the 3D part oh the SH3D, but more general problem of Java UI rendering. I was able to simulate it also with just opening combobox in the Settings menu right after the application started.