VTOL Transition MC agressively returns to previous waypoint

I have been playing with 3.9 firmware using SITL before loading it into one of our aircraft, whenever I include a VTOL Transition MC waypoint in a mission( as way point N) the following happens:

  • Aircraft reaches waypoint (N-1)
  • Aircraft pitches up to Q_Angle Max
  • Aircraft yaws agressively to point towards Waypoint (N-1)
  • Aircraft begins hovering toward Waypoint (N-1)
  • Approx 10s after hitting way-point (N-1) the aircraft aggressively yaws again to point towards way-point N + 1
  • Behaviour continues as expected for remainder of flight
    2018-08-13 23-35-03.tlog (440.9 KB)

Dataflash Log

Dataflash log here:
https://drive.google.com/file/d/1PEgcS1rpeRK2miYlulT1X0AQ7aT6QyoR/view?usp=sharing