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

When the Part is not being used by the Physics Engine, it becomes a Sleeping Part.

By walking up against it, or standing on top of it, the server manages to call the velocity change every time.

By turning off Sleeping in the Physics section of Settings, this effect can be disabled. However, this could have performance consequences, so another solution would be desirable.