https://www.mangago.zone/read-manga/far_away_from_cold/
Its doesnt exactly fits ur description but u cant try this manhua. The uke is rich turn poor (not that poor really) after fam prob and the seme is poor turn rich after he connected to his fam. Thats the gist of it i kinda forget the exact plot since its been a while.
You might forget the plot but you won't forget the Korean learning technique that I will reach you if you become my Korean learning apprentice together we can learn and strive to become true Koreans and if you think I'm not well versed in Korean enough to become your master in this heartfelt Korean journey look at this 누 나 see if you don't know what that means, you need to participate in my Korean master training . Come now apprentice, let us learn the true values of Korean together!!
Thank you!
Those tropes where Uke is the rich son and seme is poor man before past are discovered and found that uke is a fake son and so is actually penniless and seme is the son of some rich family.