SetCoreGuiEnabled Isn't Working?

Hi, the:SetCoreGuiEnabled method isn't working when I use it to make Player Gui Elements invisible. Keep in mind that I'm using Filtering Enabled so I'm using Remote Event to call the function.

Local Script (Placed in Starter Gui) :

-- Declaring & Waiting for variables
local starterGui = game:GetService('StarterGui')
local replicatedStorage = game:GetService('ReplicatedStorage')
local serverStorage = game:GetService('ServerStorage')

local events = replicatedStorage:WaitForChild('Events')
local playerAddedEvent = events:WaitForChild('PlayerAdded')

local bottomRightGui = starterGui:WaitForChild('BottomRight')
local bottomMainFrame = bottomRightGui:WaitForChild('MainFrame')
-- Deleting Core Gui's
playerAddedEvent.OnClientEvent:connect(function()
starterGui:SetCoreGuiEnabled(Enum.CoreGuiType.PlayerList, false)
starterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Health, false)
starterGui:SetCoreGuiEnabled(Enum.CoreGuiType.Backpack, true)
end)

Server Script (Placed in ServerScriptService) :

local replicatedStorage = game:GetService('ReplicatedStorage')

local events = replicatedStorage:WaitForChild('Events')
local playerAddedEvent = events:WaitForChild('PlayerAdded')

game.Players.PlayerAdded:connect(function(player)
    playerAddedEvent:FireClient(player)         
end)