Laggy object movement in VR gaia terrain,Gaia terrain cause laggy movement in VR

I’m trying to build a VR scene (with htc vive) which includes GAIA terrain and continuous object movement, but its movement is very laggy and disrupted, no matter how small the terrain, even when i remove all textures. when I deactivated the terrain itself - it works perfectly.
what can I do?

Thank you,
I’m trying to create an VR game (with htc vive) and unity. In my scene there is terrain made with GAIA, and an object that continuously moving. The terrain cause laggy and disrupted object movement. Even if I use small size terrain, and remove all textures from it, it still does that. but when i deactivated the terrain itself - the object moves perfectly.
What can I do? the problem repeat itself in several scenes…

Same thing happens to me, I have to turn off post processing otherwise it wont even load on play.

Any advise after 2 years?