1. Try to move/reposition your device in a slightly different place.
2.Check if there are any nearby large objects causing interference with your phone’s signal.
3.Make sure that there is nothing blocking the connection to your service provider, which might be preventing you from getting a signal.
4.Check your mobile device’s network settings to see if the connection is properly established.
5.Keep your device closer to windows or other openings to increase the signal strength.
6.Switch off your mobile device and then switch it back on in a few seconds.
7.Check to see if your service provider offers any signal boosting/enhancement tools.