How do I use KeyCode with Filtering Enabled?

I'm using KeyCode so players can flip through a GUI. My script works in Solo mode only (the usual with FE lol). Here is my code, help would be greatly appreciated!

game:GetService("UserInputService").InputBegan:connect(function(inputObject, gameProcessedEvent)
    if inputObject.KeyCode == Enum.KeyCode.Q then
        if SlotNum.Value <= 3 then
            SlotNum.Value = SlotNum.Value + 1
        elseif SlotNum.Value == 4 then
            SlotNum.Value = 1
        end
    elseif inputObject.KeyCode == Enum.KeyCode.E then
        if SlotNum.Value >= 2 then
            SlotNum.Value = SlotNum.Value - 1
        elseif SlotNum.Value == 1 then
            SlotNum.Value = 4
        end
    end
end)

EDIT: Another function is linked to the SlotNum Value that is located in the playergui that actually changed the color of the GUIs (although it works in solo mode so I doubt the issue lies here):

SlotNum.Changed:connect(function(newvalue)
    for i,v in ipairs(Slots:GetChildren()) do
        v.BackgroundColor3 = Color3.new(255, 255, 255)
    end
    if newvalue == 1 then
        Slots.A.BackgroundColor3 = Color3.new(0, 170, 255)
    elseif newvalue == 2 then
        Slots.B.BackgroundColor3 = Color3.new(0, 170, 255)
    elseif newvalue == 3 then
        Slots.C.BackgroundColor3 = Color3.new(0, 170, 255)
    elseif newvalue == 4 then
        Slots.D.BackgroundColor3 = Color3.new(0, 170, 255)
    end
end)