When in VR, I have noticed a reflections flicker glitch only when looking in a certain direction in a specific level.
This is what the level is supposed to look like:
I found that this was most likely caused by some kind of glitch related to the static meshes in that area.
To fix it, I simply merged and replaced all the static meshes in that part of the level and the glitch disappeared.
I hope this helps anyone else with a similar issue.
I have the same problem, especially when I run the VR preview simulation from the editor. If I pack the project and run the .exe I hardly have that problem, but it still comes up sometimes.