What is the ruling on a student hiding his school grades from his family to avoid their displeasure, knowing that he is not negligent, but they always criticize him and want him to be perfect, which contradicts "All humans are fallible"?

It is advisable to strive diligently in studies and to supplicate (Dua). It is also important to inform parents truthfully about school grades, because concealing them harms them and constitutes an act of disobedience (Uquq). Their blame and reprimand stem from their eagerness for their child's excellence, not from a desire to harm him.