Placement preview for my furniture placement system not working. How to fix?

I am making a basic furniture placement system for my game, and I am having trouble with hiding the selection box (for previewing) after the player has placed the structure.

After the player has placed the structure, it still shows the SelectionBox, but I intended to make it disappear when the player places the structure.

I am having the particular trouble in Line #35 of the Script for the server.

Script for the server:

-- Script
local ReplicatedStorage = game:GetService("ReplicatedStorage")

local MousePositionEvent = Instance.new("RemoteEvent")
MousePositionEvent.Name = "MousePositionEvent"
MousePositionEvent.Parent = ReplicatedStorage

local MouseClickEvent = Instance.new("RemoteEvent")
MouseClickEvent.Name = "MouseClickEvent"
MouseClickEvent.Parent = ReplicatedStorage


-- Preview the placement
local function PreviewPlace(Owner, PositionBase, StructureBase)
	StructureBase.UserOwner.Value = Owner.Name -- Assign Owner
	
	local Position = CFrame.new(PositionBase)
	StructureBase:SetPrimaryPartCFrame(Position) -- Move the structure
	
	-- Make it look like it's being previewed
	local Selection = StructureBase.SelectionBox
	Selection.Color3 = Color3.new(0, 255, 0)
	Selection.Transparency = 0
end
MousePositionEvent.OnServerEvent:Connect(PreviewPlace) -- Mouse position event listener


-- Place the structure when the user clicks
local function Place(Owner, PositionBase, StructureBase, DestinationFolder)
	local NewStructure = StructureBase:Clone()
	
	NewStructure.Parent = DestinationFolder
	NewStructure.UserOwner.Value = Owner.Name -- Assign Owner
	
	-- Hide the selection box after player has placed structure [I AM HAVING TROUBLE WITH THIS!]
	local Selection = StructureBase.SelectionBox
	Selection.Transparency = 1
	
	print(Owner.Name .. " has ended placing a " .. NewStructure.Name .. "!")
end

MouseClickEvent.OnServerEvent:Connect(Place)

Script for the client:

-- LocalScript
local ReplicatedStorage = game:GetService("ReplicatedStorage")
local MousePositionEvent = ReplicatedStorage:WaitForChild("MousePositionEvent")
local MouseClickEvent = ReplicatedStorage:WaitForChild("MouseClickEvent")

local Players = game:GetService("Players")
local Player = Players.LocalPlayer

local Mouse = Player:GetMouse()
local MouseCFrame
local MousePosition

local SelectedStructure = game.Workspace.OakWoodBeam -- The selected Strukchur
local SelectedStructureAmount = 3
local DestDir = game.Workspace -- Destination Folder for placed structures

local Placing = true -- Placing Status

Mouse.Button1Down:Connect(function() 
	SelectedStructureAmount = SelectedStructureAmount - 1
	
	if (SelectedStructureAmount == 0) then
		Placing = false
	end
	
	MouseClickEvent:FireServer(MousePosition, SelectedStructure, DestDir) -- Trigger function place() in server
	
	print (Placing)
	print (SelectedStructureAmount)
end)   

-- Updates the mouse CFrame, and updates server about it
function UpdatePosition()
    MouseCFrame = Mouse.Hit
    MousePosition = MouseCFrame.p
	
	if (SelectedStructureAmount >= 1 and Placing == true) then -- If structure amount is not yet 0
		MousePositionEvent:FireServer(MousePosition, SelectedStructure)
		return true
	else 
		
	if (Placing == false) then -- Place the Structure when the user clicks
		return false
		end
	end
end

-- Game loop [CLIENT]
while true do
	UpdatePosition()
	
	--print (Placing)
	wait()
end

How would I fix it?

The selection box should be handled locally, as it's something only the player that it's relevant to should see. This would also significantly make the code cleaner and easier to manage.