Animation replicates only in client, but not in server?

I'm testing on starter characters and when animations get loaded, they only replicate in the client, not in the server or other clients. Is there something wrong with my code:

--Animation Module
local self = {}
local Animation
local Track
function self:StopTrack()
    Track:Stop()
    Animation:Destroy()
end

function self:PlayNewTrack(Id)
    if not game.Players.LocalPlayer.Character then return end
    if not game.Players.LocalPlayer.Character:FindFirstChild("Humanoid") then return end
    if Animation and Track then
        self:StopTrack()
    end

    Animation = Instance.new("Animation")
    Animation.AnimationId = "rbxassetid://"..Id
    Track = game.Players.LocalPlayer.Character.Humanoid:LoadAnimation(Animation)
    Track:Play()
end

return self

Photo Is it a bug from ROBLOX or a bug from the StarterCharacters