I probably got the wording wrong. I really don’t know how to describe the problem by words, I will still try.
When I’m looking at the mesh model, let’s say from above, I can see the back face, but not the front one. When I look from below, I can see the front face, but not the back face. I imported all.
I made the mesh on Blender, and it looks just fine. What’s causing this and how do I fix it?
Late response. I found out that the normals of some objects were messed up, I fixed them manually and then re-added them back on Studio. That fixed the issue. Your suggestion also works btw, so thanks for that lol.