Apm 2.5, 3.1.5 AutoTrim Problem

Hİ All,
I used to fly with my V frame qudcopter for a while, but yesterday without changing anything, during the take of quad, moved fastly to forward and i was landed witout any crash but after this point unable to take off stabilised again.

Issue is I am arming the quad, and try to take of but it is aimed to go forward, i manualy give backwards pitch and keep quad in hower by manually giving negative pitch all the time.
After i decided to Auto trim and trim the quad in air. After doing this, quad is howering OK but in the mission planner i am observing that quad is staying at -10deg pitch although it is paralled to the ground.

I have downgrade to many firmwares and upgrade it again to 3.15 but nothing changed. I have checked frame escs, radio props etc. everything is okay but problem is still ongoing.

I have uploaded logs and graphs for my couple minutes of hower please have a look at,

I would re-calibrate the accelerometer, it looks like the apm/copter was not perfectly level when you initially calibrated. Refer here (copter.ardupilot.com/wiki/initia … -hardware/) for instructions. “The level position is the most important to get right as this will be the attitude that your controller considers level while flying.” I think AutoTrim is more for fine tuning (small adjustments) while flying.