I agree with everything you said.
The first chapters were so good, and while it's good that they tried to give Junoh another image or decided to made him a more deeper persona rather than just being the crush of the MC, the way the story was developed is so bad that it ruined its first chapters and charisma.
Your second paragraph summarize the biggest problem on this. If Minoh hadn't ask him about what was wrong, then I would understand why did he tell all his problems to the other guy. But Minoh was there just waiting for him, and even noticed something wrong without Junoh telling him. So why is that he can noticed the damage to this "friendship" and not noticed, or even better do something about his romantic relationship with the guy that has been worrying about him since this story began?
I'm on the verge of dropping this manhwa. Everyone is annoying and frustrating except Minoh and Gitae. We're reaching toward the end of the manhwa but this drama still hasn't ended. I feel like the ending won't make up for it because Junoh & Minoh might half assed made up or the author might give it a rushed ending. I used to click on the notification so fast when this manhwa get updated but now i just roll my eyes and sighed.
While y'all might be hating Changhyun to the core, I fucking hate Junoh with all my guts. I don't get how he tells everything to Changhyun because he feel "comfortable" like BITCH you have a whole caring boyfriend that'll listen and love you and yet you're telling me you're more comfortable talking to the asshole who bullied you?
Junoh is a fucking mess. I can rant all day about him. He just does whatever he wants and has no consideration for other people's feeling. He's been through a lot, I fucking get it but isn't it time for him to move on and live a happier life with Minoh. It's like he's still living in the past. Ignoring Minoh and use "trying to forget about Jaehee" as an excuse is so unnecessary. If he really like Minoh he'll be able to forget about that purple twig by loving Minoh more and more each day. Trying to distance himself won't fucking make him feel better, he'll feel even more isolated.
Overall, the author probably trying to drag this manhwa just so they could get more chapters published