Had this problem for a while but until now I only saw it as a brief flash. Today I almost got through into UE4 inner dimension 
Any idea what’s causing this and how can I get rid of it?
Engine version is 4.20.3, Vive headset.
happens in both forward and deferred modes.
Doesn’t happen when I remove actor that is using scene capture to render ui widget on custom mesh. Trying a workaround by disabling those components between usage but no luck so far.
So the culprit was actor with ui widget component, causing the glitch when just outside the edge of vision. Fixed with combination of setting widget visibility with parent’s WasRecentlyRendered and increasng widget BoundScale to 2x. Took me only half a day ;(