Animation not being loaded properly

Hello there. I’ve rigged this step stool object onto my character, by connecting it with the HumanoidRootPart, something I’ve done several times before that never caused any issue. I’ve also made a pose using it, but when I play it in-game, the character’s lower torso doesn’t move accordingly to what it’s supposed to. However, the step stool does.

This is how it looks like in the animation editor.

This is how it looks like in-game.
While in both pictures the step stool correctly levels itself at the center of the root part, the character does not level itself correctly, landing below the intended spot.

I should also mention this rig was modified using the Transform tool, in case it might have anything to do with it. Any ideas?