I’m assuming you mean AOA Mina, so I will break it down based on everything I know. I will say right now you’ve made comments in the past about being “innocent” but some of the things she’d done get quite dark. And that goes to anyone reading, I’ll censor stuff that may be sensitive.
Jimin was the leader of AOA, and so that obviously comes with needing control over the group. It’s likely that Mina felt Jimin was attacking her when she was trying to do her leader duties. Other sources have also come forward and said Mina didn’t like waking up on time for schedules or being where she was supposed to be, which is likely a reason as to why Jimin had to be harsh on her.
Mina accused Jimin of things such as this, as well as not being understanding of her dad’s death. Mina seemed very mentally unwell so Jimin and the other AOA members apologised to her. During this apology both Mina and Jimin threatened themselves with knives and the situation was very intense, but overall they apologised and the members left. However, Mina did not give up despite this. Even though Jimin left AOA and left the industry Mina kept attacking her. She would write very long posts on Instagram going more and more into how Jimin destroyed her mental health, as well as talking about how irresponsible Jimin was even going as far as to talk about Jimin’s… private love life… which was entirely unnecessary. Her posts went from just talking about her situation to obsessive. Mina would post gory photos of slit wrists, which weren’t even her own and were instead found on a gore website, which triggered many people who followed her, and she continued to make posts about Jimin, begging her to answer her texts and calls even though she supposedly wanted nothing to do with her. Then it came out that Mina had been seeing a boy who had a girlfriend, and as soon as this news came out, Mina dragged Jimin right back into the situation. It started to become clear that Jimin likely hadn’t done anything, and Mina’s severe mental health issues were causing her to exaggerate and obsess over Jimin. Mina would even go as far as to harass Jimin’s friends
I personally don’t see Mina as “problematic”, at least not as problematic as other idols, but rather extremely unwell mentally. But it’s also unfair to call Jimin problematic when she had her life destroyed by something that wasn’t even true