When crouching, the character go under ground

Hi, I’m new here. Today I have some issues that I could’t solve.
If you have any ideas or have the same problems before, please leave a comment. I’ll do my best to try to understand and learn!

Problem describe:

I was finding some “smooth crouching” method for the game, and I found this useful post:

[How to write a smooth crouching script in blueprint?][1]

I follow the step in the answers and everything works OK, but instead of just crouch, my whole character’s body sank into the ground.
And I also noticed that the character’s capsule still stay in the same position.
So I tried to adjust the “Capsule Half Height” and other options(not all of them), but it doesn’t work…

The animation itselve has no problem I think…

If you need more info and detail, please let me know!

244635-standing.jpg

244636-crouching.jpg

The Event Graph and Hierarchy is here:
244639-