Character animation is weird when it is played on the game.

I’m using UE5.3.2. I copied Animations from LyraStarterGame for play character animation in my project. However the character mesh turn to weird shape when it played with equipment animation. It is the link how the animation works.

I’m using LinkAnimClassLayers node to change character unarmed animation to pistol animation. When i move the character, skeletal mesh is deformed. I don’t know why it happened. And i don’t even know key-word to research about my problem. How can i make the animation going to be play normally?