[HSY] Teens not being able to achieve goals while attending highschool with them

While playing with both my teenage sims while they're in the High school Building, they go to class and then they stand up not longer attending to class and If I select that they do it, they spam right back up with the other class attendees, and I can not make my sim Study for exam for example also while going with them to the high school, I'm not a mod user.

Edit By crinrict: Added pack tag to title.