Unity Vr [Google Cardboard]- UI Render issue

I am facing rendering issues for our VR project meant to work on android.
All the black color in the UGUI ( world canvas ),while rendering on the mobile device, turns to white artifact.
I tried several , options like disabling post processing and different quality settings.
But can’t seem to solve the issue.
Please let me know if anyone can solve this issue.

This is the normal image

This is how it renders in the game.

if you mean, black part should not be transparent,
Then adjust that in the texture import settings., Disable Alpha is transparent