How can i fix my tween not working as intentional?

So i have created an AI for a boss fight in my game with 2 functions

local function MoveTo(target,lookat,duration)
	spawn(function()
		if tween ~= nil then
			tween:Cancel()
		end
		
		local TI = TweenInfo.new(duration,Enum.EasingStyle.Linear)
		
		local goal = {}
		goal.CFrame = CFrame.new(target,lookat)
		
		script.Parent:SetPrimaryPartCFrame(CFrame.new(script.Parent.PrimaryPart.Position,lookat))
		
		tween = ts:Create(script.Parent.HumanoidRootPart,TI,goal)
		tween:Play()
		wait(duration*1.001)
		if tween ~= nil then
			tween:Cancel()
			tween = nil
		end
	end)
end

and

local function MoveSquare()
	spawn(function()
		MoveTo(Vector3.new(-445,4.1,-450),Vector3.new(-445,4.1,-450),2)
		wait(2)
		MoveTo(Vector3.new(-285,4.1,-450),Vector3.new(-285,4.1,-450),2)
		wait(2)
		MoveTo(Vector3.new(-285,4.1,-610),Vector3.new(-285,4.1,-610),2)
		wait(2)
		MoveTo(Vector3.new(-445,4.1,-610),Vector3.new(-445,4.1,-610),2)
	end)
end

for some reason, 100% of the time that MoveSquare was called, it would set the boss to 0,-1000000,0 for no reason, all other MoveTo uses in the script works perfectly fine so it doesn't make sense.

Is there any way this can be fixed?