Servers by jDrones

Plane rolling left in Auto mode

APM 2.6
My plane flies level and straight in manual mode and in FBWA mode.
No trim or subtrim on elevators or ailerons.
As soon as I switch to Auto mode it flies along with the left wing dropped about 20 degrees.
It only just started doing this. What could be the problem?
Plane has been calibrated and APM set level

Servers by jDrones