Twitch in flight when full stick to opposite full stick

The problem
when we fly at full speed in one direction and go full stick the opposite direction the drone “wobbles” on perpendicular axis.A video and example log can be found here:

This only occurs in loiter mode, not in alt hold.

this issue is form ardupilot version 4.1.4 and onwords, all the way up to 4.3.4, 4.3.5 not tested yet. The issue doesn’t happen on 4.1.3 and previous.

Please let me know if you need any further information.
Thank you.

@Michael_Oborne I don’t know either randy nor lennards tag (sorry)

The link has an access requirement.

@rmackay9 @Leonardthall log showing the twitching on direction change

Yes sorry, fixed it. my apologies.