FBX Animation Import Issue

Hey friends! I'm working on my first game and for the last few days have been struggling with an animation issue in my project. Thought I'd ask here if anyone knows how to solve it.

I got this cat model from the Unity store and it's working well. For one of the scenes, I need to modify the existing animation from the package. So I took it to Cinema 4D and made few tweaks, exported it back to FBX and dropped it back in Unity.

I applied the same import setting the original FBX had, but for some reason when I'm trying to use any of the animations from the new FBX file with the original model, it goes all over and looks super weird. On the other hand, if I just use the new file in the project, the animation works okay.

Any ideas what I'm doing wrong in terms of importing new animations?

Video to show the problem here (animation is a placeholder haha):

Thank you