Copter behaviour

00000071.BIN (777.1 KB)
00000078.BIN (628 KB),
Dear Team,
I have made quadcopter with pixhawk 2.4.8 and the Frame size is 450, I have set the initial parameters and flew it. The log file 71 & video attached flew well without any oscillation. I try to fly it again in ten min gap observed that the copter started moving wihtout any input. Log file 78 and video attached for reference. Didnt have any clue what made it change the behaviour of the copter without applying any input on Pitch and Roll. Please advise