What would make unreal ignore my UCX_ physics mesh?

All I’m doing is making a custom cone primitive, different from the default. But unreal seems not to like it for some reason. I made it in 3dstudio max just as all my meshes and gave it the prefix UCX_ as always, but it just wants to make a low poly auto-generated mesh for some reason. can anyone clue me in?

Hi!

I think you forgot to add a numerical suffix to the name of your custom collision mesh. You should add a digital prefix even if you have only one mesh collision. This is very important.

Mesh name - MyBigMesh

Collision mesh name - UCX_MyBigMesh_001

It doesn’t work.
UE 4.27 just ignores any and every collision.
Who knows what magic is required for a collision to work, but some times it just doesn’t work for some meshes.
I totally does import those UCX_whatever, with or whithout indexes postfixed.
But some times it just doesn’t use em.