
The plot is the same to Solo Leveling... but not that much.. its just...why???.

I think it's because the plot is moving too fast, and we already know that he's way at the top. While Solo Leveling takes it time and builds the plot up, we also know that despite Jin Woo's op-ness, there are still people stronger than him.
But, this is a good manga to wait out Solo Leveling's break.

You're not wrong, the start is indeed very similar, although its starting to diverge. Based on the current story so far, it seems that this manhwa will go interstellar or Sci-Fi-ish as hinted by mars colonies and battleships in space which is something i've never seen in a reincarnation story before. I'm very much excited for the space arc (๑•ㅂ•)و✧

If you read carefully both the Seme and Uke at the last story like to have sex. they didn't considered their relationship serious, for them it was for fun... The Uke realized he doesn't want to share his man to anyone anymore. And when the seme saw the uke being push he realized he can't live without the Uke. He just run to culprit to solve the problem. And he thinks their bestfriend is there to take care of the uke while he was solvinf the issue.
at the end they realized they love each other and won't cheat anymore....

First of all, "Like to have sex" is not synonym for cheating. Now, the one who should read carefully is you it seems. From the manga it states that it's three years into their relationship. The seme was the one who wanted the serious relationship from the start and deleted all the uke's contacts from his phone. The seme never spares a thought after the uke. He goes after the culprit even after the uke asked him to stay.
Is this the other version of solo Leveling?