COLLISION WONT IMPORTED WHEN USING "IMPORT INTO LEVEL BUTTON"

hi! i’m gettin really frustrating problem and need your help. i have a scene made in blender.


as you see, i have 1 collection from external file that consist of 1 mesh and couple of collisions.

this image belongs to external blender file.

when i wanted i to import in to unreal , i used to “import into level” button in order to get instanced static mesh.


meshes are all good, but collisin meshes come seperately and renamed and all collisions disappeared

if i import single instance from external file, everything works perfectly.

my question is why “import into level” function rename whole scene with new names for each mesh, and how can i avoid it.