Plane changes mode to rtl by itself

Ground Control Software Mission Planner
1

hello, this message appears to me on mission planner when I was flying my plane and the mode changes from auto to RTL although the failsafe was disabled, what this message means ? (RC input: decoding DSM(1))

2

it means it detected DSM for the rc input protocol. and is normal assuming you have a DSM rx

3

thanks, sir @Michael_Oborne
for your reply , I appreciate it