Custom Humanoid Hitbox

So I’m trying to have a custom humanoid hitbox and I found this post which pretty much accomplishes what I want

There are only one issue:
if the custom collider part is too eccentric (XZ plane) on initial parent to character then this behavior happens:
But in the other scenario shift lock behaves weirdly by tweening to the desired shift lock:

Also strangely if I change the part size after parenting to character then the collision “fidelity” changes with it but the original behavior of either glitching or tweening is still maintained

Here is a place repo (change collider size inside ServerScriptService.Script.Collider)
Repro.rbxl (30.1 KB)

To clarify, I am interested in both why it happens and how to fix it


the problem is you put the mesh part is cancolide turn it off it should be done because the part is following the head so i hope this will help you