Material turns black, when I put another Mesh with Opacity on top

This is my first try putting stuff into Unreal, so I probably made a few mistakes.
I made the material in Substance designer, made a few planes in 3Dsmax with unwrap und put it in unreal
Everythings works fine except for the floor. I have one Material with a frame and pipes and another grate material; with the height and tesselation the grate should sits under the frame, but on top of the pipes
When I biuld the like, the frame/pipe material turns black

It’s hard to see, could be bad lightmap or not enough light…

Hey Juni, can you post how you built the material that isn’t displaying correctly? Also, not sure if you have ray-tracing active in your project, but if you do I know that ray-tracing doesn’t work with displacement and tessellation in Unreal, at least not as it normally does, which can result in textures turning black in areas that fall below where the originally geometry was.