Why doesn't tool animation play even at the high priority?

local Gun = script.Parent
local Hold = Gun:WaitForChild("Hold")
local Sprint = Gun:WaitForChild("Sprint")
local Reload = Gun:WaitForChild("Reload")
local Crouch = Gun:WaitForChild("Crouch")


Gun.Equipped:Connect(function(part)
    print("equip")
    local humanoid = Gun.Parent:WaitForChild("Humanoid")
    print(humanoid.Parent)
    print(Hold.Parent)
    local HoldTrack = humanoid:LoadAnimation(Hold)
    HoldTrack.Priority = Enum.AnimationPriority.Action
    HoldTrack:Play()
    print(HoldTrack.Priority)
end)

Here, no errors are printed. I've tried to set priority to highest, and also checked with the last print in the function that it is set to Action. I'm trying to get Hold animation to play while the player is holding the tool. Help appreciated, thanks!