I tried to move my flight mode to Altitude holder when I was flying but when I around 2 meters from the ground the drone tries to land.
When I give some more power to adjust the altitude, the drone jumps like there is a bad reading of the sonar but I checked the logs and it seems to be good.
Do I have too much noise on the accelerometer ? Do I need to tune the altitude PID ?
did you try to set the middle throttle? I had around the same issues but I have resolved with the attached procedure.
See at: copter.ardupilot.com/wiki/ac_throttlemid/