You can re-set the connection between the Classe100x and your WiFi line directly from your smart phone with the DOOR ENTRY app.
From the Hamburger button at the top left of the app, click on the specific submenu "Settings" => "Set Wi-Fi video entryphone"
Follow the step by step instructions that the app will provide you with interacting with your Classe 100x
The wifi LED on your Classe 100x will continue to flash until the connection to the WiFi network is restored; after thise operation the Wifi led will turn off.