TRAINING: 5 trainings to get a bump in inside defense. Seriously! Seriously! One of the more enjoyable parts of this game is training yet it get's old when it takes forever to get a bump. It quite simply shouldn't take this long to get a bump. The guy was 25 when I first started, just turned 26 so it isn't like he is an ancient artifact!
You leave out a lot of details. My 23y old SG didn't pop for four straight weeks in JR, so what? He's not that young, 193cm tall and JR trains slowly.
How tall is the player? We also need to know what are his inside skills to see if there's any negative elastic effect there. What trainer are you using? Are you doing 1 or 2 position training? You can't just say "5 trainings for a pop!" without any details except for his age. 25 trains pretty slow.