In my point of view, I notice that when I move my crosshair, it follows the arm.

But in the view of other players, they don't see that my arm is moving.

This is the bone for the gun:

And the animation for the gun:
idle:

Running:

In my point of view, I notice that when I move my crosshair, it follows the arm.

But in the view of other players, they don't see that my arm is moving.

This is the bone for the gun:

And the animation for the gun:
idle:

Running:

I don't think there is enough information for us to help. If you are synchronizing your game state over the network, it's likely a problem in your application code that isn't applying the animations correctly on the other client.
That's okay I figure it out thank you.