Regenerating magic gui not working?

This script is to display how much magic you have and change the size of the magic bar depending on the number (number value) but when your magic goes down it stays there and doesn't increase as it should

Can anyone tell me why

local player = game.Players.LocalPlayer

game["Run Service"].RenderStepped:Connect(function()
    local num = game.Players.LocalPlayer.Character.Magic
    script.Parent.display.Size = UDim2.new(player.Character.Magic.Value/player.Character.Magic.MaxMagic.Value,0,1,0)
    script.Parent.HP.Text = ""..num.Value.."/"..player.Character.Magic.MaxMagic.Value
end)


if player.Character.Magic.MaxMagic.Value > player.Character.Magic.Value then
    repeat wait(0.3)
        player.Character.Magic.Value = player.Character.Magic.Value + 3
    until player.Character.Magic.Value == player.Character.Magic.MaxMagic.Value
end
if player.Character.Magic.Value == player.Character.Magic.MaxMagic.Value then
    player.Character.Magic.Value = player.Character.Magic.MaxMagic.Value
end