While loop not working but while true loop does?

Why does this not work:

while itemName.Value ~= "none" do
    wait(.0001)
    print("item value is not none")
    gui.Visible = true
    gui.Position = UDim2.new(0, mouse.X, 0, mouse.Y)
end

While this does:

while true do
    wait(.0001)
    if itemName.Value ~= "none" then
        gui.Visible = true
        gui.Position = UDim2.new(0, mouse.X, 0, mouse.Y)
    end
end