This could simply be a case of not being willing to learn enough. In uni, there are so many things going on - parties, friends, lectures, societies, the list goes on. Perhaps your mind is set on one of those, rather than your work at the moment. As harsh as this sounds, it can sometimes be the case, so it's worth considering. However since you've come onto a Mental Health forum, I'd personally doubt that this is the case.
It could also be a case of symptoms of anxiety. Having thoughts running through your mind all the time and worrying about so many things can cause us to lose concentration on anything. In that case, you'd need to look at ways of easing the anxiety. What is it that is worrying you at the moment? Write your thoughts about it down. Engage in meditation to help ease the anxietyx
Much love <3