Auto-trim is damned whatever it does.
Auto-trim is a has been with us some time and has been known for causing trouble. Pilots first began to run afoul of it with the early autopilots that would trim unbeknownst to the crew-until it then kicked out and left the crew with a handful.
Some implementations of FBW require autotrim to function properly and it can simplify the job of flying. Autotrim has teeth however, and pilots who regard it as piece of the furniture in the cockpit and thus lose awareness of what is doing stand a great chance of being adversely surprised by it.
That is why most of the modern aircraft have noisemakers associated with trim movement. But one major airframe maker skipped this step. Why is that?
And the answer to the pop quiz is the Ethiopian B-737 at Beruit. For whatever reason, PF didn't want to handle the aircraft that night, but the A/P never relieved him. Don't you guys want to earn your pay for flying?