my 3d is overlapping itself

I created a 3D map in Blender, but when I imported it into my project, the objects overlapped like Blender’s “in front” option.

Forget the issue, how where you able to make such nice graphics work in GDevelop?

I don’t know what I’m looking for in that image. Could you describe the issue in more detail and indicate where we should be looking for that in the image?