Large monster gets pushed by small player character (Capsule Collision issue?)

I’m making a large monster, but a small player can push it.

  • Monster Capsule: Half Height 800 / Radius 700

  • Player Capsule: Half Height 96 / Radius 42

When the player moves into the monster, the monster gets pushed.

I suspect that when the capsule radius becomes large, the bottom area widens and allows the player to get slightly underneath, causing this issue.

Expected:

  • Both should block each other

  • Small characters should NOT be able to push the large monster

Tried (didn’t work):

  • Very large mass value

  • Disabled “Enable Physics Interaction”

To isolate the issue, I tested using the default ThirdPersonCharacter from Unreal Engine with no additional variables.
Engine Version: UE 5.4
Test Project:

https://drive.google.com/file/d/1UVv-buqr9XMNokQiPMHCr3YyzsHaP_BY/view?usp=sharing

How can I prevent this?