Opacity not working as it should

I’m trying to insert people in the scene, but here is the problem - opacity is not working as it should - the area where the texture should be transparent, it’s just darker.
I’m using latest v-ray for sketchup


On CPU it renders as it should

I was looking at supported features in v-ray docs, but I couldn’t find anything related to the opacity.
Texture is PNG with transparent background and in the opacity map I have a black and white that same image. I have tried with “diffuse texture alpha” as well, but same result.

Thank you!