Question on MK15 mechanism

Dear QGC Dev community,

this link describes my problem (Unexpected behavior on RC fail in Auto mode - #2 by Truth_T) and I have a question for anyone who have many knowledge about the mobile(android) QGC’s mechanism.

in the take-off location, there was only a ground control station (GCS) and a joystick. At the delivery destination (an island), an MK15 was present, with power on.

while autonomous flight, the GCS lost connection due to poor LTE connection, and my copter suddenly received a message to go to waypoint #1. I suspect that the MK15 sent a DO_SET_WAYPOINT command to the copter when it was connected from a far range, due to unknown reason.
because there is no source of DO_SET_WAYPOINT command excepts for MK15.

Can someone please confirm if this is a possible scenario?

Thank you in advance for your help.

Duplicate of Requesting help to anyone knows mechanism inside of MK15 QGC.