Why won't this check the GUIs position?

local player = game.Players.LocalPlayer

while true do
    if player:WaitForChild("PlayerGui").StartGui.StartFrame.Position == Vector3.new(0.4,0,1.01,0) then
        player:WaitForChild("PlayerGui").StartGui.StartFrame.Visible = false
        player:WaitForChild("PlayerGui").StartGui.ClasssFrame.Visible = true
    end
    wait(1)
end

why won't this work? it should check out the guis position is that and the change the properties to the guis.