I’ve try it in both source 419.2 and binary 419.2 . And it is reproducible. No matter in package game(develop&Shipping) or PIE.
VR device: HTC vive and vive pro
DisplayCard: GTX 1070/1070ti/1080ti
CPU:E3 1230 v3 / I7 7700K
Project:My Game project / VR Tempolate(all the settings are default)
Situation 1
Drop a 3D widget in the map(just a few button,no function.Empty level).Play it in VR mode. No matter your camera face it or not, the framerate will begin to drop. The longer you wait the more serious it will show out. I have seen it drop from 90fps to 75fps after 25~30mins.
Situation 2
Do the same thing in situation 1 . And then jump into another level. No matter this level has 3D widget or not the framerate seem like being ‘extend’.It will not going back to 90 but still in 75fps(or very unstable). Until you close the whole game and open it the framerate back to 90fps.
Situation 3
Drag the same 3D widget into the level and set it as ‘Actor hidden in game’.The problem won’t happened.
Situation 4
No 3D widget actor in the level but 3D widget component in my Pawn. Same thing happened.
Hoping this report may help!