How to fix the Preview Base Pose from Anim Offset?

I’m using a Montage to play the “aiming” animation setup everytime I hold the aim button, but I wanted to make the body to follow the mouse, so I added all that script with the Yaw and Pitch thing from this tutorial:

The blueprint part looks fine to me, but it messes up in the Anim Offset.

I have the aimCenter pose (for the offset) and the aimLoop (for the montage; the “idle” base pose).

–When the Preview Base Pose is set to none, it looks like this: - YouTube

–When I use the aimLoop as the Preview Base Pose, the offset looks like this: - YouTube

–When I use the aimCenter pose as the Preview Base Pose, the offset looks like this: - YouTube

The aimCenter is set to Mesh Additive and the aimLoop is set to Not Additive. Is it a problem with the animation? Or the skeleton? I don’t know how to fix it!

I appreciate your help.

I feel like I need to show how the blueprints are, so here is a video of how everything is set up: - YouTube