Can't stop my animation

I have a problem with Stop(), I can’t use stop the animation but the function can. How I can fix it?

if interact == false and script.Parent.Interact.ProximityPrompt.ActionText == "Hide" then
		script.Parent.Interact.ProximityPrompt.Enabled = false
		interactpart.Position  = interact2.Position
		hrp.Anchored = true
		humanoid.AutoRotate = false
		tween:Play()
		wait(0.2)
		HUT:Play()
		hiding()
elseif interact == true and script.Parent.Interact.ProximityPrompt.ActionText == "Unhide" then
		script.Parent.Interact.ProximityPrompt.Enabled = false
		interactpart.Position  = interact1.Position
		IUT:Stop() -- The animation can't stop at this line
		UUT:Play()
		unhiding()
		wait(0.5)
		script.Parent.Interact.ProximityPrompt.ActionText = "Hide"
		script.Parent.Interact.ProximityPrompt.Enabled = true
	end

	local function decreaseTimer()
		timer = timer - 1
		if timer <= 0 then
			script.Parent.Interact.ProximityPrompt.Enabled = false
			interactpart.Position  = interact1.Position
			IUT:Stop() -- The animation can stop at this line
			UUT:Play()
			unhiding()
			wait(0.5)
			script.Parent.Interact.ProximityPrompt.ActionText = "Hide"
			script.Parent.Interact.ProximityPrompt.Enabled = true
			return
		end
	end