Animation causes rigidbody to move

I have a problem with a strafing animation where about halfway through the animation, the rigidbody (which is on the same object as the animator) moves a bit to the left, although applyRootMotion is false on the animator, and it always happens at the same point in the animation. If I set isKinematic to true or remove the rigidbody, it works fine. No force is applied to the rigidbody through any script (except one that sets the velocity to zero in FixedUpdate) or collision and it's constrained on y movement and x and z rotation. I have a capsule collider on the object and a convex mesh collider on a child object (a sword) which intersect, but this is no problem in any of the other animations. The only animation where the problem occurs is the one from this pack called "Strafe_90HipsLeftFaceFwd", and I deleted most of the keyframes as theres lots of stuff in the original animation clip I don't need. I have no idea how to fix it (or at least prevent it), so I'd love if someone could help me.