SW3D 6.1.2
Linux Mint 19 x64
Nvidia 2060 @ 418.56

When I attempt to display my model 3D in a separate window that window is blank. Flipping back to normal view works fine.

Creating a new model works in the separate window. Opening an old one doesn't.

I have 3 monitors but am forced to use only one, which is somewhat annoying.

Any ideas?

I'm using version 6.1.2 on OpenSUSE tumbleweed, x64, proprietary nivida driver 430.14, a quite old GTX 650 Ti, and two monitors. I have no issue with displaying the 3D model in a separate window. However SweetHome3D won't even complete startup unless I modify the startup script and add
Maybe that might be worth trying. (Put the additional -D parameter anywhere before or after the other -D definitions.)