To add to the million repeated responses, I happened to fly with a Alpa training rep at United , he said the the guys that have been at XYZ regional for 15 plus years have the highest failure/termination rate. Said the numbers just don’t lie . Old dogs stuck in their ways and have a harder time learning new tricks I guess. I was pretty surprised by the numbers he was showing me of guys having problems and their backgrounds. Meanwhile the young kids surely
Don’t have the same history , will learn anything you show them . I mean give a 2 year old a iPad , 30 seconds later he works it better than you. Meanwhile Tom 57 who still uses DOS 2.0 gets overwhelmed by it .

The OP may not have any issues in training and may be a star , but the guys before you have not paved a pretty path for you , it seems.

Best of luck , frustrating I know . Keep at it .