I found a way for fixing it by my self.
The Touchbar Controlboard is attached to a flex cable under the Logicboard and for some reason the Touchbar Controller broke due to a clean install maybe? So i bought a new one from AliExpress for 8€ and changed it the replacement was super easy. Only the logicboard has to be removed you dont need a new Touchbar for this. After that all it needs is a reboot with a wired internet connection.