Nah don't thank me, OP was the one who originally noticed and posted it. I don't even know a lick of kr lmao
Bruh ngl, (as a disclaimer me saying this doesn't mean I don't appreciate human-made translations) BUT sometimes idk who calls the shots but they really change or omit certain words phrases and it changes the vibe of the story.
A bit oot, for instance in the dangerous convenience store, the iconic ahjuicy was changed to mister. and he calls the mc boy it gives me the ick Idk if all translations were like that but man it kinda made me feel so disappointed especially since i bought the physical copies which contains these translations
Oh also i don't think he was trying to be manipulative when he was saying hyung, but due to the situation it can come across that way. According to OP, jaeyi often says hyung not just in this chapter, but the past ones too but ugh since the translations omitted many it's hard to keep track unless we know kr.

https://x.com/BonsoirElle/status/2108205395915198966
It's kinda sad how many parts of Jaeyi calling Ideum hyung got cut out(/TДT)/ if this story was animated, I can imagine the softness and sulkiness of Jaeyi's voice as he says hyung.