Why is my model not moving with the player?

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#1

This was a YouTube tutorial but I have slightly adjusted a few of its properties to make it work.
I’m using Runservice.Stepped so it constantly matches the velocity of the player with the moving model. But I don’t get those results?

local tweenService = game:GetService("TweenService")
local runService = game:GetService("RunService")

local positionStart = CFrame.new(11.409, -0.378, -268.977)
local positionEnd = CFrame.new(11.409, -0.378, -305)

local object = script.Parent
local objectRoot = object.PrimaryPart

local tweenInfo = TweenInfo.new(3, Enum.EasingStyle.Back, Enum.EasingDirection.InOut, -1, true)
local tweenFunction = tweenService:Create(objectRoot, tweenInfo, {
	CFrame = objectRoot.CFrame * CFrame.new(0,0,-30)
})
	

while true do
	tweenFunction:Play()
	wait(1)	
end

local lastPosition = objectRoot.Position

runService.Stepped:Connect(function(_, deltaTime)
	local currentPosition = objectRoot.Position
	local deltaPosition = currentPosition - lastPosition
	
	local deltaTime =  0.016666
	local velocity = deltaPosition / deltaTime
	
	objectRoot.AssemblyLinearVelocity = velocity
	
	lastPosition = currentPosition
end)
#2

Found a solution, It was because I had to put the while true do part at the very last because the script would’ve ended there.