How come my sims keep failing university classes

Are you willing and able to use mods? I have found a mod that allows me to check my sims grades during the semester. The grades always start at zero at the beginning of the semester and it acts like a meter which you slowly fill by going to classes, do homework and make papers/presentations. It does not change how they earn grades but let's you know if they are doing bad. In those cases I get them a study book to study for their course. My sims would have done way worse in uni without this mod.

https://modthesims.info/d/637945/quickly-check-uni-performance.html