Hello,
When I try and import a model, using FBX format, with custom collision (by having a second model, named “UCX_(modelname)_001" or "UCX(modelname)” ), the collision fails to import. Further, even if I have auto-generate collision unchecked, Unreal generates the collision anyway. This seems to be an importer error.
fixed. The collision part of the mesh was improperly set up, it was slightly concave, and had holes in it, and unreal just simplified it, and removed triangles, making it look auto-generated.