Menu, tools, manage a-GPS state, reset and then download; calibrate both pitch and roll and then compass.
If anything will help with GPS accuracy, that will.
BTW, from that dev:
- Samsung phones: Because of a firmware bug, they may report extreme battery consumption for GPS Status even if it is not running at all (other programs using sensors are affected too). This is harmless and no power is consumed! Just ignore it and let's hope that a future firmware upgrade will fix this on your phone.