Lockout issues on Pixhawk

I have had my Pixhawk lockout 3 times now I am not sure why. I am using a Futaba 7008sb receiver with single Sbus wire to pixhawk, and T16iz transmitter, occasionally it will put the ailerons, flaps etc. hard over and I need to restart everything, only a matter of time before this happens in the air. We went over all the settings and no fail safe settings are turned on.
Any ideas why?

Power problem, connector problem, who knows without details