Try pushing harder? Maybe you are using a top cap that is too big, unless you are using VertX's top cap.
I would recommend pushing harder. Sometimes it is kinda tight to get hic bars on. I can guarantee you they aren't defective. Bar diameter is something that is kinda hard too screw up haha.
Yeah, I noticed when Trevor and I traded HIC shims, that my bars were much harder to get over the shim. Just keep at it, eventually they'll slide on and all will be right in the world.