OpenGL not working with VNC

I’m not able to get OpenGL graphics to work normally through my VNC connection. My eggplant machine and SUT are both running on Linux platforms and I’m using the latest free version of RealVNC. Oddly enough, if I rotate the orientation of my SUT’s monitor, I’m able to see graphics, but I don’t actually want to do that. Do you have any ideas for why this may be happening?