I was unable to reproduce this issue on our end. I did found that fullscreen will not bring up the VR mode in a packaged build. I also find that you could use the Console command “Stereo on” to enable VR mode and you could do this on begin play with in the level blueprint. You could also use the short cut Alt+Enter . However, I could not reproduce some levels being in VR and other not.
Quick questions:
Can you reproduce this issue in a clean project?
If so, could you provide a simplified project so that I could take a closer look?
We have not heard back from you in a few days, so we are marking this post as Resolved for tracking purposes. If you are still experiencing the issue you reported, please respond to this message with additional information and we will offer further assistance.