Why does FilteringEnabled break the arms of my script off?

Ok, so, I just made a script, a bad one indeed, as its arms keep breaking off. I am suspecting FE for this. This is the same issue Black Magic had. Now, here's the code:

--Script, ServerScriptService

local WhiteList = {'Liquid_Napalm', 'thinknynoodles', 'Arozak', 'ProSLix'}

local ReplicatedStorage = game:GetService('ReplicatedStorage')

local FirstRemoteEvent = Instance.new("RemoteEvent", ReplicatedStorage)

FirstRemoteEvent.Name = 'FirstRemoteEvent'

game.Players.PlayerAdded:Connect(function(Player)
		
	for i, v in pairs(WhiteList) do
			
		FirstRemoteEvent:FireClient(Player)
	
	end
	
end)

--LocalScript, StarterGui

local UIS = game:GetService('UserInputService') --Variables

local Players = game:GetService('Players')
		
local Player = Players.LocalPlayer
		
local Character = Player.Character
	
repeat 

	wait()

until Character
		 
local RA = Character['Right Arm']
		
local LA = Character['Left Arm']
		
local Torso = Character.Torso
		
local RSH = Torso['Right Shoulder']
		
local LSH = Torso['Left Shoulder']
	
local RW = Instance.new('Weld')
		
local LW = Instance.new('Weld')

Effects = Instance.new('Model', workspace)

Effects.Name = 'Effects'
	
local ReplicatedStorage = game:GetService('ReplicatedStorage') 
	
local FirstRemoteEvent = ReplicatedStorage:WaitForChild('FirstRemoteEvent')
		
FirstRemoteEvent.OnClientEvent:Connect(function()
		
	RW.Part0 = Torso --Positioning of the arms.
		
	RW.C0 = CFrame.Angles(math.rad(90), math.rad(0), math.rad(-70))
		
	RW.C1 = RW.C1*CFrame.new(-.25, 0, .2)
		
	RW.Part1 = RA
		
	RW.Parent = Torso
		
	RSH.Parent = nil
	
	LW.Part0 = Torso
		
	LW.C0 = CFrame.Angles(math.rad(0), math.rad(0), math.rad(45))
		
	LW.C1 = LW.C1*CFrame.new(0.15, -.15, -.15)
		
	LW.Part1 = LA
		
	LW.Parent = Torso
		
	LSH.Parent = nil

	UIS.InputEnded:Connect(function() --Animating/lerping the Right Arm.
			
		for i = 0, 1, .5 do
			
			wait()
			
			RW.C0 = RW.C0:Lerp(CFrame.new(0, 0, 0)*CFrame.Angles(math.rad(90), math.rad(0), math.rad(-70)), i)
					
		end
						
	end)	
		
	local function OnZPressed(Input, gameProcessed)
			
		if Input.KeyCode == Enum.KeyCode.P then
	
			for i = 0, 1, .5 do
			
				wait()
			
				RW.C0 = RW.C0:Lerp(CFrame.new(0.72, -.1, -.5)*CFrame.Angles(math.rad(90), math.rad(0), math.rad(0)), i)
						
				if i == 1 then		--Effects.
				
					local Part = Instance.new('Part')
				
					local BV = Instance.new('BodyVelocity', Part)
					
					BV.MaxForce = Vector3.new(math.huge, math.huge, math.huge)
				
					BV.Velocity = Character.HumanoidRootPart.CFrame.lookVector * 108
			
					Part.Parent = workspace.Effects
				
					Part.Anchored = false
				
					Part.CanCollide = false
				
					Part.CFrame = RA.CFrame
				
					Part.Size = Vector3.new(.05,.05,.05)
				
					Part.Transparency = 1
				
					local Fire = Instance.new('Fire', Part)
				
					Fire.Color = Color3.fromRGB(231, 157, 236)
				
					Fire.SecondaryColor = Color3.fromRGB(199, 0, 166)
				
					Fire.Heat = 25
				
					Fire.Size = 2
					
					local Sparkles = Instance.new('Sparkles', Part)
					
					Sparkles.SparkleColor = Color3.fromRGB(248, 142, 255)
				
					wait()
				
					Part.CanCollide = true
				
					Part.Touched:Connect(function(obj)
						
						if obj.Parent ~= workspace.Effects then
						
							print(obj)
								
							local Explosion = Instance.new('Explosion', Part)
							
							Explosion.Position = Part.Position
							
							Explosion.BlastPressure = 50
							
							Explosion.ExplosionType = Enum.ExplosionType.CratersAndDebris
						
							Explosion.BlastRadius = .01
						
							wait(1.5)
						
							Part:Destroy()
						
						end
				
					end)
				
				end
					
			end
						
		end
			
	end
			
	UIS.InputBegan:Connect(OnZPressed)		
		
end)

So, I tried this in the Studio's test server, and also in an actual server. Whenever I try to use it, or someone joins the server, the arms break off. I expected the script to work just like this: Player's character is loaded, their arms are positioned using welds, their shoulders are removed, pressing 'P' will lerp the RightArm and it shoots some magical thingy. If the answer to the problem is in the Roblox Developer Wiki or the Developer Hub, please post a link to that article. Anyways, thanks for taking out the time to read this.