I made a waypoint mission (flight plan) containing 15 waypoints and no POIs.
End of mission is set to RTH.
I flew the mission without problems.
After landing I turned off the Air 3 and attached the wide angle lens.
Turned on the Air 3 and flew the same mission again.
Now the drone activated RTH at WP13 !!
After landing I checked the mission and the last 2 waypoints were gone ??

Not sure what's going on here in this situation. I just made a 15 point mission, ending with RTH upon completion. Had it execute it, worked with but one issue, but it wasn't a waypoint issue, will explain afterwards. Once completed the A3 RTH'd as expected. Saved the mission. Powered down the drone and RC2 controller. Powered everything back up and selected the mission again and it flew every point without missing any. The issue I had was that the mission would ultimately make a complete circle but on the last point instead of completing the arc of the circle, backed itself up for alignment with the last point. That could be my error though as I've never setup a waypoint mission before. But otherwise, it did all waypoints both times successfully.

Hi there. Sorry about the inconvenience. If you experience this very often. please try refreshing the firmware of both units using the DJI Assistant 2. Thank you and have a nice day.