I was flying today, big open field, no interferences, compass and IMU calibration performed, 12-16 satellites. I always start off with green "Safe to Fly GPS" signal. However, at random times during flight, it turns yellow and I get the "Safe to Fly Non GPS" signal. It doesn't seem to affect my flight at all though. A few times, I believe I was in a hover when it randomly switches but doesn't seem to affect the hover. Checking my flight on HealthDrone, I see "mode changed to GPS ATTI"