Dw, the next 2 chapters will definitely make you happy bc the things you’re complaining about not happening happen in the next 2 chapters just be a little patient and don’t judge before it’s completed. We are still in the middle of the climax and in stories things are still revealed through the climax and into the exposition of a story.
I’m still not going to say this is the best mystery story of all time but you gotta remember this is the author’s second work and this is their first mystery. Honestly for a non adaptation short story I’d say the author is doing really well for their first time.
I’m not saying that they can’t have criticism but when you are doing it on an illegal platform where they aren’t going to see it it’s just complaining. Real criticism can only happen when the author can actually see the feedback so they can grow from it. Like I’d argue putting what you said on social media is 100 times more productive than doing it on here.
But yeah you probably are just lucky. The amount of stuff I’ve read over the years with way worse plot execution with 3 times longer chapter lengths is insane.

Thinking on it now...this is kinda nothing? I know this is a shorter series, but since the whole thing is a mystery, I wish we got to know the characters, piece together clues. Just finding out who the killers are isn't super interesting since we don't really know them; it's just like "oh, okay." While I didn't want Gyeonwoo to be the killer, Yiyoung spending the most time with him made it interesting. Or, I'd THINK. Neither character is super fleshed out (Yiyoung's backstory we got two chapters ago took a while and hasn't come back into play yet), so the romance/dynamic isn't super interesting. So it feels like the author wanted a unique angle/dynamic and didn't achieve either for me.
Now to be fair, we still have 7 chapters left, so romance/character exploration could happen, but since the jig's up for the mystery aspect, that was a bummer.