What's happening with this animation?

I'm extremely inexperienced with animations. I'm trying to use an animation to make my character hold a pistol correctly.

Whenever I equip the pistol, the animation starts playing. Whenever I unequip the pistol, the animation stops playing.

It works just fine on the client, but when I view my character from another client or from the server, it doesn't seem to play properly:

https://gyazo.com/6ebb2e5068509f7cb9e05ee2c390ad02

The animation I'm using is 5 seconds long, all of the keyframes are the exact same, looping was disabled in the animation editor, and the priority of the animation was set to action. The AnimationTrack instance is created by the client whose character contains the pistol. I have looping disabled because if it's enabled, the animation plays endlessly, even if you unequip the pistol and call :Stop() on the AnimationTrack.

Does this kind of behavior viewed from another client or on the server result from the client/server not recognizing the priority of the animation or something?

Why is this happening? How can I prevent this from occurring?

Set the Animation Priority to "movement". The problem is that the character's default animations are overriding your shooting animation. Go to your animation editor, click on the top left button, click "SetAnimationPriority" and click "movement". There will be 4 priorities (Core, Idle, Movement and Action). Idle will override core, Movement will override Idle and Action will override Movement. The roblox character's default animation has "Idle" for priority.