Hello!
When you connect a car for example via Icom and you want to switch to an ethernet connection you have to let the car sleep for a while so the ZGW (FEM_GW/BDCGW) can reset. After some minutes you can connect your ethernet cable. That's a normal behavior and has nothing to do with Authex. You can also disconnect the battery for 10 seconds, this will help in the same way.
CU Oliver