In the fanfiction, it could be that Hermione is becoming too involved in Hogwarts politics or academic rivalries. Harry, who is more concerned about the bigger threats like Voldemort, might tell her off for getting distracted. Additionally, if Hermione starts to show favoritism towards certain students or groups within the school, which goes against Harry's sense of fairness, he would be likely to express his disapproval.
One reason could be Hermione's excessive worrying. She often frets over small details and Harry might get tired of it and tell her off. For example, if she keeps nagging about the proper way to perform a spell when they are in a hurry during a dangerous situation.
Maybe Hermione has been too pushy with her academic knowledge in the fanfiction. Harry, who might be feeling stressed or frustrated, tells her off for not considering the emotional and practical aspects of a situation. He could say she's being too much of a know - it - all and not listening to others' ideas.
Molly could have made some inappropriate comments about Hermione's blood status. Even though Hermione is a Muggle - born, she has proven herself time and time again in the wizarding world. If Molly makes a snide remark about her blood, Hermione would surely tell her off for her prejudice.
In some fanfictions, Hermione might be so focused on following the rules that she opposes Harry's more risky but potentially effective plans. Harry, being the more action - oriented one at times, would tell her off for not being more flexible and trusting his instincts.
I haven't actually read that specific fanfiction, so I can't summarize it directly. But generally in such a plot, Harry might tell Hermione off due to a misunderstanding. Maybe he thinks she's being too bossy about schoolwork or how they should handle a certain situation in the wizarding world. It could also be related to her over - protectiveness of Ron or some other complex relationship - related issues.
One possible reason could be to protect himself from the pain and loss he has endured. After all he's been through, like the death of his parents, Sirius, and so many others, turning off his emotions might seem like a way to avoid further hurt.
It could also be due to a series of unlucky events. Suppose Hermione's well - intentioned plans keep backfiring in a way that makes Harry question her judgment. Like when she tries to solve a problem but ends up making it worse, Harry might start to lose trust.
Another reason could be that there are some misunderstandings between them. For example, Hermione might misinterpret Harry's actions or words as being too reckless or irresponsible, and she decides to push him away to avoid being dragged into what she perceives as a bad situation. Also, it could be related to her own insecurities. She might feel that she is holding Harry back in some way or that their friendship is becoming too complicated, so she takes the step of pushing him away to simplify things.
One possible reason could be that she is in a desperate situation. Maybe she needs something for a very important spell or potion to save someone's life and she thinks Harry won't notice or will forgive her. For example, if there is a rare ingredient that only Harry has access to and time is running out.
Another reason could be a rift in their friendship caused by outside factors. For instance, if the wizarding community starts to turn against Harry because of false rumors or misinformation, Hermione might find it too difficult to stand by him. She may fear for her own reputation or safety, and this could lead to her abandoning Harry.
Another reason might be related to his family. In some fanfictions, his parents' story or his relationship with his family members could be distorted. Harry has a strong connection to his family, especially his parents, and any wrong portrayal of that could make him pissed off.