1. Internet Connection: Check that your smartphone is connected to the internet with a stable connection.
2. Proximity: Ensure your smartphone is close enough to the charging station for a proper connection.
3. Restart the App: Try restarting the SIXT app and attempt to end the charging session again.
4. Contact Operator: If the issue persists, contact the charging station operator for further assistance. You can find their contact number on the charging pole.