Thanks for the info! I was using the release 9.2.5 to test, but realized that only master has those interactive settings you mentioned. The tests get reported as failed on my setup (HTC VIVE Pro on an NVidia Quadro P5000) due to multiple errors like this:
vtkOpenGLFramebufferObj:368 ERR| vtkOpenGLFramebufferObject (000002BEE65E77F0): failed at glDeleteFramebuffers 16 OpenGL errors detected
But they seem to run completely fine despite these errors being reported.
As for our original issue, as I said, I do suspect our special setup of running VR in a separate thread (i.e. not in the main application thread, because that is driving our “other” GUI) is probably at fault here, I will try and come up with a minimal reproducible example.