AmiGO uses GPS positioning technology and the performance of that depends on many factors, such as the amount of buildings around you, the weather, etc. It also depends on your smartphone's GPS hardware and software.
Another common issue on Android phones is the Battery Saving settings. In some scenarios when Battery Saving is enabled, the GPS is disabled. This means that AmiGO no longer knows where you are. You must disable Battery Saving for AmiGO to run properly on your device.