why does the Server miss velocity changes?

In an attempt to understand how servers use velocity, I set up a simple scene where a Part hasa server script inside of it that makes the block change color and hop up every three seconds. However, the block manages to stay still while changing color the vast majority of the time.

Here's the code used

while (true) do
    script.Parent.Velocity = Vector3.new(0,50,0)
    script.Parent.BrickColor = BrickColor.Random()
    wait(3)
end

Is there something about the Roblox engine I need to be aware of, or did I approach the implementation wrong, or is there an error I'm missing?

Thanks