Had my first odd situation with the DD app today after many successful flights last year. I was surveying a hillfort archaeological site which covers a ridge over 800m in length. With some extra ground added around the margins of the flight map I reckon the total length of the flight plan was 850m max. The idea was to position myself centrally on the ridge and let the drone fly out to both sides 425m max from my takeoff point, therefore staying within the 500m distance limit in the UK. Unfortunately, to keep line of sight in both directions I could only take off from a location one third of the way along the ridge on the highest point. This meant that one side of the ridge flight was possibly 500m or just over.
When I set the flight to start the drone rose up 1m, hovered, then descended and landed again. The intevalometer had been triggered and the drone was taking pictures until I turned it back off.
Is it possible that the app calculated that that the flight length from take off point to start point was over the UK and DJI limit of 500m and aborted the flight ? If not, why would the drone behave like this ?