I too am gobsmacked, that in this day and age Airbus have managed to design another generation of machine that doesn't do what you could reasonably& logically expect.
That's not how the system works. Yipoyan is confusing an autopilot trimming against a pilot induced control input with the normal FBW response. If the crew here had pushed on the stick with sufficient authority, at any speed, the trim would move nose down to match that response.
This is not correct. When the system is in alternate law the auto trim function is disabled. Pushing the stick forward only results in limited elevator motion. Trim must be addressed by the pilot in this mode, so simply pushing the nose down isn’t going to retrim, the pilot has to do it manually.
This still doesn’t address why the trim was moved to the 13 degree nose up position.