This usually has a technical reason and has an easy way to resolve.
Technically moreViz works by copying the contents of the host application and pasting them into the moreViz client for viewing in any VR environment. The host application internally opens a newly indexed (“numbered”) OpenGL window. moreViz allows to configure which OpenGL Window to brige to Virtual Reality on the fly.
To switch the model bridged to VR, please follow this brief guide: