350 problem following flight plan and anothers things, big bugs

The A350 doesn't follow the flight plan correctly, regardless of the wind direction; the artificial horizon isn't horizontal. After 12 hours of flight, a stall on approach occurs; the aircraft spins around, and after manual recovery, the A350's flight director (FD) no longer follows the ILS or the programmed speed. I have to complete the approach and landing manually. Then, once the thrust reversers are engaged, it increases speed as if it were in a TOGA to regain altitude. The A350 has become unmanageable, and the same goes for the A340. Thanks, Inibuild. After 12 hours of flight banked to the right, ending up in the woods is not ideal.