I might be 20 years old but those 6 outside shooting and 2 jump shot trainings begun when he was 18 years old...
And my trainer is level 5.
I don't think you understand what I'm saying. Let me put it this way: 6'9 is tall. Tall players train outside skills fairly slow (and JR is the slowest of all of them). Tall players that have some age train outside skills even slower than that.
So no, I'm not at all surprised it takes as much as it does to train your player, and I do not at all think it is out of the ordinary or a bug.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."