vray matte shadow not working on 3.4?

[fraggle]

Hello
I'm trying to get a plane as matte over a white background to compose the shadow in post prod, but I can't get it to work neither with the vraymatwrapper or with the Vray property object.
First: The plane 1 should return the same alpha than the plane 5:
Plane 1: matlwrapper, -1, affect alpha on, shadow tick.
Plane 5: Vray matter p^roperty, -1, affect alpha on, shadow tick.
I also notice that other plane with alpha set to 0 or 1 doesn't return the right value too.
Is it a bug or it's me that doesn't understand how it works?

Thanks

[Zdravko.Keremidchiev]

this seems to work fine on our side, can you attach the scene?

[fraggle]

Here is the file.
vray_matte_trouble.zip

[svetlozar.draganov]

None of the planes actually has a V-Ray Wrapper Mtl assigned, all planes are with regular V-Ray Mtl.
When Wrapper Mtl is assigned with the appropriate values everything works as expected:

[fraggle]

You're right, but that's weird, as the screen shoot attached in my first post showed the assigned mat to object.
Probably a max trouble instead of a vray one.
Thanks to have taken the time to look at it anyway.