I've been out testing the new firmware updates for ST16 and also the H and in particular the ability to switch from GPS to Non GPS while flying. I was in a small open field for the test and only did it twice each time when switching back into GPS from Non GPS it caused the H to act strangely. This was all done with "Turtle" setting. Winds were dead calm with partly cloudy skies. 1. The first time I switched back from Non GPS to GPS while moving sideways at no greater a speed than 5 to 8 mph it shot across the field at about 25 to 30 mph for about 40 ft. I'm not sure why it stopped after that distance either my stick activity or it found where it liked to be in GPS. 2. The second try it moved vertically up and down about three or four feet with slight drift and then settled back into GPS. When in Non GPS it flew very smoothly and going from GPS to Non GPS was not problematic, it merely resulted in a slow drift due to momentum. Next week when I have time to return for more testing I'm going to a much larger field and testing so I can try and see what produces the variance in it's behavior when switching from Non GPS to GPS. I hope others chime in on their experiences. I will also test with another H and H Pro. To see how behavior varies with three different drones. Perhaps my flight logs will reveal something as well. Another explanation could be the factory serviced repair I had done after the H took a dip in a glacial stream in Iceland perhaps it's still got some issues from that episode. If your inexperienced at flying without GPS I would also use a large field to test how yours performs or not do it at all.