Why does the character hit an invisible wall when importing .FBX from Blender into Unreal engine 4?

Question

3D

What is the point. I'm creating a location for the game - an underground tunnel. In order not to create everything entirely, of course, I decided to make it modules. When importing into the engine, I wanted to see how my creation fits into the environment, what dimensions, etc., but in the end, when I tried to enter the tunnel, I came across an invisible wall.
I puzzled for a long time how to get rid of this, tried to play with the Collision Responses settings, tried to break the models into very primitive pieces, but it didn’t help. (According to my personal guess, fbx is saved as a transparent box with a mesh inside, I could be wrong, correct me if anything.) I’ll make a reservation right away
that I’m still a beginner in this all, everything that I do, I do on pure enthusiastic traction, therefore Perhaps the question is elementary, but I could not find anything that could help.

Answer 1

The decision came by itself. Initially, in my understanding, "divided into primitive pieces" was divided into an arch, part of the floor and an additional piece. The problem was solved when I divided the arch into the little blocks that make it up, and then exported them from the blender, selected, but not merged into one mesh. In this form, the empty space is not filled with invisible walls; when imported into the unreal, they are displayed as separate meshes, but when they are selected all at once and moved to the world, they themselves are located relative to each other. Hope it helps someone.