Oculus Rift - strange glitches on spiral object

Hi all,
I’m making a game in VR for Oculus Rift. Everything going great but I got some strange glitches on spiral object when player move head.

Here are some samples:

Here you can see glitches on botton of the gates(whitish parts that will jump with headset movement).

I’m using Unity 2019.1.14f1.

Antialiasing help with some elements but spiral one have this circle shadow on it.

Any idea how to fix that?

Try changing the realtime shadow resolution, make sure that mip maps are on but this looks like a shadow issue.