The Miele app cannot access the domestic appliance.
Check whether your router’s WiFi is activated. Many routers have an LED that shows the status of the WiFi.
Check that your home WiFi network is activated and that your domestic appliance is connected to it.
Check the WiFi reception quality on the display of the Miele domestic appliance.
If necessary, reset the WiFi connection between your Miele domestic appliance and your WiFi network.