I have a problem with a TRB140. The sim card is inserted and the correct PIN is entered. In the status overview, the correct provider and a db reception level are displayed very briefly. However, the display then changes back to disconnected and the device continues to search for a connection.
The SIM card can immediately establish a connection in a mobile phone and connect to the mobile network.
I have already tried entering the APN manually or setting it to AUTO.
I have also tried setting 2G/3G/4G manually or automatically.