I am using a fixed wing plane with a pixhawk autopilot system. After all the setup done, I was checking the Flight Mode operation. When I turned to Auto Mode, it is switching to RTL mode.
I think it is due to Failsafe or any other related safety reason.
Plane switches to a RTL when there is no mission uploaded/ current mission is complete. Try uploading a new mission and you can see taht the AUTO mode will work as expected.
I understand that. I got confused when I saw Auto mode (when Auto mode executed) the previous day and RTL mode (when Auto mode executed) on the next day.