Mine's the same mate. I honestly have no idea what it's all about. There's a thread somewhere on the TDU forums about it.
I actually changed it by going to my modem settings, and there's a box there called UPAP (or some such), and you're meant to enable that. When i do that, it's all green, full core open. When i disable it, it goes orange like you have. I dunno, i can still play, i can see other players. I'm not sure what it does, and in the thread they have, it's not really explained in plain english, so i honestly have no idea.
Maybe i should try both, and get someone to see if they can see me, or invite me? Maybe it's something to do with that?