I agree with what you said.
The way I see it as well is that the author has lost track of how to tell the story.
He might have had Yahwi in his mind as the end game before the hiatus even now but found himself thrust into space by the negative reaction the story received. Mainly regarding the black-haired character with all the stuff he did to Jooin.
So now it feels like the author is writing the story as he goes. He spent 2 or more months, after the hiatus, trying to fix Yahwi to see if more people would lean toward liking him since he is supposed to be the end game for Jooin.
But seeing that the majority of the readers are leaning towards Cain because they reject the abuser now, I feel like he (the author) does not know where to take the story anymore.
wth, author???
Right before the break, we get this growth arc centering on Jooin's stance with Yahwi's wishy-washy behavior in never standing up for Jooin when he could have easily stopped the rumors, to wanting Jooin to stay by his side...even though he only shows affection when it suits him.
We get it. Jooin felt like a weak loser for falling for Yahwi, twice, and being burned and nearly ostracized for it both times, so now he's going to stand on his own two feet and push past it all by deeming anything related to Yahwi as Bad.
As for Cain, it still unclear how this was supposed to be handled. Was he just there as an experience for Jooin in how a real relationship should feel? Was he there to add growth to Jooin becoming more mature?
Because Jooin is not mature in the slightest. He's being a brat and he refuses to listen while hurting those close to him.
He may have had his reasons, but being completely unforgiving doesn't get you anywhere. You just end up more angry.
I think this would have been better handled if Jooin had a real honest talk to Cain about his feelings for Yahwi and that while sleeping with Cain was a heart felt experience, that he can't use it to cover up unresolved feelings, which should segue in Jooin telling Cain that he'll be loyally friendzoned.