Some Animations replicate, and some don't. Why would this happen?

Hello! I'm having trouble with animations replicating. For my game I made a custom character and made my own movement animations, which replicate fine. Then, I went to make a gun. I'm using an animation to make the character hold the gun in a certain position. For some reason, the gun holding animation isn't replicating! I've tried playing through both Animator and the Humanoid and playing through the server for some reason straight up doesn't work. The script for the player movement animations is in StarterCharacterScripts (the ones that replicate) and the script that animates the gun holding is in the gun tool. (the one that isn't replicating.) Any reason why this would be happening?