Inspire 1 Z3 vs. M600 X5 on same map - M600 stopped mid map and hovered

OK. I have DroneDeploy questions.
I just did a couple test flights of the same map. I flew the DJI Inspire 1 with the Z3 Camera and the DJI M600 with the X5 Camera. I created a flight plan on DD and copied it and saved it as two flights, one for each. The Inspire flew the flight plan with no issue. It took all the pictures like it was supposed to. I launched the M600 in DD and it flew about half the flight plan, stopped and hovered. I was able to take control, bring it back and land it while the remote was still in F mode. I turned everything off, M600, Remote and Tablet. I get it all back up and running and reset the start point to start from the beginning again. I launch in DD and the M600 stops in the same location, about halfway through the flight. I take control without switching to P mode on the remote, bring it back and land it safely. It took pictures like it was supposed to but why would it stop in the same location and go into a hover. I have it set to return to home if we lose signal. It stopped when it was closer to the takeoff location so losing signal would be more likely to happen when it was at its farthest point away. The flight plan was about 35 acres. Do you have any idea why this may have happened?