Render CustomDepth pass make Render In Main Pass enable on Android?

Hi all. I want to make a occlusion mask for my AR project? (mean make a invisible ROCK but will occlusion and hide any object behind that ROCK).
I use bRenderCustomDepth to check if a object is behind that ROCK, and disable bRenderInMainPass to make that ROCK invisible. It work when run on PC but when run on my Pixel 3, the ROCK is visible and i figure out that if I turn off the bRenderCustomDepth, the ROCK will invisible.
Is bRenderCustomDepth make bRenderInMainPass enable on Android or any way to make invisible rock like my idea (invisible but can hide any object behind it).

Thank you very much.