The accusations of misogyny mostly come from how the webtoon portrays some female characters and gender-related issues. Critics felt that certain arcs depicted women, especially female students and feminist characters, in a stereotypical or overly negative way, while male authority figures were often presented as the ones who had to “set them straight.” Whether someone sees it as misogynistic depends on their interpretation, but that’s the main reason the series received criticism. The controversy wasn’t just one scene, but a pattern that some readers noticed throughout multiple story arcs.
In my opinion, even when female characters wanted to do something for themselves or assert their own goals, it often felt like their concerns were downplayed or treated as less important, which added to the impression that the story didn’t handle its female characters particularly well.

Just a heads up for anyone wondering why a lot of us stopped supporting this series after Chapter 125: the author got involved in a major controversy involving racist depictions, the use of the N-word, and storylines that many readers felt promoted xenophobic views. The backlash was so severe that WEBTOON removed the series from its English platform and the creators issued apologies.
I actually enjoyed the live-action adaptation, but I personally stopped supporting the original manhwa after Chapter 125 and won’t be reading anything else from the author.