So I had this massive area to fly and capture vertical imagery and decided to use waypoints. I had tested it twice before in wide open areas so was confident enough with it. I calculated that I would need 10 flights to cover area and had everything planned out. Weather was perfect wind was 3m /s.  The first 3 grids flew flawlessly and the fourth flight started perfect with the Inspire flying straight up to 100m and then to waypoint 1. About half way along line one it seemed to brake sharply and I could hear the motors rev even though she was 100m up and about 250m away from me. I put it down to her trying to keep at 7m/s speed. Second line flew perfectly and then on line 3 it started to do it constantly. Like as if someone was constantly forward and backing on the right stick. The bird looked really unstable and the tiltmeter was showing blue going in all directions. I had to cancel the flight and bring her down manually. No issues here. Job cancelled and she hovered perfectly and I brought her home totally as expected. Checked all props and locks etc and re-took off and completed this flight manually as only had a few more photos to capture.Moved location to area 4 and again, this time half way along line 1 the same thing, all over the place back and forward. Had to fly grid manually. Fifth area decided to reduce frid speed to 5m/s to see if that would make a difference and the only difference was the jerking didn't look as extreme and the bird didn't look in danger of flipping or a prop flying off !!!! Ended up then flying all remainder of my grids amnually without a flaw.
Hopefully someone else has seen this and either has a solution or its a known issue and will be fixed. BTW all compass calibrations etc were done.

Thanks

Paul

I never had this exact problem you described, but had others. When you save a waypoint and you load it for a flight, DO NOT chose the flight mode "Consistent with the record" (I guess its called that)

Always chose consistent with the ROUTE - the record option will reproduce every slight movement you make during flight, and I guess its bugged a bit. My guess that it will count previous wind speed and correction into your actual flights.

However if you use the Route option - which is the best for photogrammetry, it will fly from point A to B, and will ignore all previous staff recorded.
I use route option for photogrammetry and it works really well, I work with pix4d 2.0 so far, but will check some other software.

BTW What massive area you are flying that you need 10 flights!! You can easily cover 3-5km/ flight in waypoint mode, so I guess you were mapping a whole village