Problem on landing with ArduPilot

Hello, guys

I have BIG Problem now…

I’m interesting in drone programming so I bought APM and Pixhawk clone and Pixhawk Cube

I have flown many drones : X380 and cc3d and Syma toy drones and Tarot ZYX-M

and I also flied RC Helicopter and there was no problem with landing.

but I have problem with landing with pixhawk…and I feel much of stress…

at first I built S550 with Clone APM and it was so unstable even after autotune and I always land it in acro mode.

So I changed FC. APM to Pixhawk.

but it had same symptom. its flight become very stable but when I tried to land it becomes unstable.

I activated Ground Compensation Variables but it didnt work.

soft landing didnt worked so I cut the throttle down right after landing but it also didnt worked

I think Ardupilot’s response for the stick feels very different with others when it lands…

I adjust copter’s attitude till it completely lands but it seems not appropriate for arducopter…

I usually fly it on the lawn… can it be the cause of problem?

How I can solve this problem?

and in waypoint navigation it lands well…

I land the copter in alt hold mode and stabilize mode.

and done roll axis autotune only in pixhawk and pixhawk cube now…

but with apm, after complete autotune with all axes, it still lands starange and tumbles on ground…