If you got a new frame, which sounds like you did, then there was a tolerance issue with the old frame that affected something. Once they decided a new frame was in order, the diagnosis stopped there. I don’t believe the factory has any obligation to tell you anything more. Imagine the “tin hat” crowd wanting to know the serial range, what did and didn’t work, ammo, day of the week and moon phase... They would drive the factory people crazy thinking they do, might, think they could, have a related problem and owe them some kind of fix. These things have a great warranty and nothing else but sending it home (like you did) will result in a clean bill of health.