Wing with pixhawk4/FW-ardupilot flies curvy straights

I fly a Skywalker X8 with the Pixhawk4 (FMUv5) with the Pixhawk FW. Everything is programmed via QGrouncontrol on the tablet. Flying so well, had to set only the roll / pitch PID values almost to minimum. GPS Waypoint’s and circles are very accurate with “px4FW”.
Now to the problem, I would like to use the Ardupilot FW, among other things because of the AutoTune function. Everything went very well in the beginning, Manual, Stabilized, FBWA, then AutoTune and here too the standard PID’s were almost halved.
But now in GPS mode (FBWB, Loiter, Waypoint’s / Auto, Circle) he flies curvy straights. Have already adjusted with the L1 controller parameters (NAVL1_PERIOD, NAVL1_DAMPING, etc.), no improvement.

Enclosed the log file and ask for help.

This flight was at 60km / h, when I go to 40km / h it gets worse, higher speeds improve the “straight” course, so the Cicle is not a straight line, but it should be a real circle.

I believe you are running the ardupilot flightstack.
For better support I suggest using their discuss (