Stamina bar isn't resizing

Help and Feedback Scripting Support
1

I want to make a stamina bar that is drained when the player is sprinting and increases when player isn’t sprinting, and the sprinting works, the stamina bar won’t resize when I sprint. I haven’t tried anything else since I have no idea.
This is the script for sprinting I put under starterplayerscripts:

local Players = game:GetService("Players")

local UIS = game:GetService("UserInputService")

local player = Players.LocalPlayer

local character = player.CharacterAdded:Wait()

local stamina = script.Stamina.Value

UIS.InputBegan:Connect(function(input, GPE)
	if input.KeyCode == Enum.KeyCode.LeftShift then
		repeat
			task.wait(0.055)
			character.Humanoid.WalkSpeed += 1
			stamina -= 100/30
		until character.Humanoid.WalkSpeed == 25
	end
end)
UIS.InputEnded:Connect(function(input, GPE)
	if input.KeyCode == Enum.KeyCode.LeftShift then
		repeat
			task.wait(0.055)
			character.Humanoid.WalkSpeed -= 1
			stamina += 100/45
		until character.Humanoid.WalkSpeed == 16
	end
end)

And this was put under the stamina bar:

local stamina = game:GetService("StarterPlayer"):WaitForChild("StarterPlayerScripts").Sprint.Stamina

stamina:GetPropertyChangedSignal("Value"):Connect(function()
	script.Parent.Size = UDim2.fromScale(math.clamp(0.65*stamina/100, 0, 1), 0.713)
end)

Any help would be greatly appreciated!