Custom preview visualization error!

Hi everyone,
I have been trying to use the Custom preview for different Geometry with different material. it seems to work in Shaded & wireframe display modes like this

But if I change the display mode to Rendered or Arctic mode all the material becomes just one type like this

I don’t know what could be the reason. Anyone else come across such issue yet?

This has been fixed I believe in the 7.6 service release candidate.