Hi! Today I was flying the following route on Xbox when all of a sudden during the last steps of the climb, the autopilot switched off and the aircraft banked heavily to the left and down, activating TOGA LK. I cleared that and managed to level off the aircraft, then re-engaging autopilot.
It did not, however, follow the set course or follow the set altitude. The aircraft also didn't accelerate and struggled to maintain speed at flight level 320. I had to end the flight since the FMC and thus, the airplane, was unusable. I remember having this same issue sometimes on the A310 as well, although on a different route. No directs or SEC FP were used.
LEBB 12 - AMTO4B 12 - TANGO - GODO2J 06R - LEPA ILS 06L-Z
The issue happened somewhere after WP TANGO. Weather was set to a clear preset.