SerhiyUk Hello!
Please check the tracker settings for the server and the port specified in the unit settings, APN, as well as the availability of funds on the SIM card that you use with the tracker.
If you have a Sinotrack ST-901 tracker, then please try to select this device model from the Hardware category. Please do not forget to change the server and port in this case.
If the problem persists, please write to us about it at support@gps-trace.com indicating your username and tracker IMEI.
