Why isn't this replicating to the client?

Help and Feedback Scripting Support
#1 
--tweens the aura up and down as well as rotate it

--variables
local tweenServ = game:GetService("TweenService")
local upPosition = script.Parent.Position + Vector3.new(0, 3, 0)
local downPosition = script.Parent.Position


--creating movement tween
local tweenInfUp = TweenInfo.new(
	3,
	Enum.EasingStyle.Sine,
	Enum.EasingDirection.InOut,
	-1,
	true,
	0
)
local tweenUp = tweenServ:Create(script.Parent, tweenInfUp, {Position = upPosition})
tweenUp:Play()

--rcreating rotation tween
local tweenInfRotate = TweenInfo.new(
	3,
	Enum.EasingStyle.Linear,
	Enum.EasingDirection.In,
	-1,
	false,
	0
)
local tweenRotate = tweenServ:Create(script.Parent, tweenInfRotate, {Orientation = Vector3.new(0, 360, 0)})
tweenRotate:Play()

I have this script inside of the handle in an accessory. When I play the game, it doesn’t move- but when I switch to the server, it works fine.

Notes:
-The accessory is inside of a humanoid
-The humanoid is not always a member of workspace, and ends up being cloned into it (regardless it still works on the server and not the client)

#2

if it works fine on server then its not an issue with your script, probably more of an issue with what type of script local or server, and where you are doing your cloning and parenting, from client or server.

Is the accessory parented to a player, or an npc? If npc (which is what it sounds like) is the npc created (cloned and parented to workspace) by a local script, or a server script?

#3

everything is server script and its an npc