If I'm not mistaken, Bojji knows sign language, right? Why doesn't he use it in times like that? There's a higher chance he'll be understood if he uses sign language.
The story is getting repetitive quickly. It's always the same plot: the main character enters a dungeon as a low-ranked guy, the dungeon turns out to be stronger than expected and he ends up saving the day.
The main plot (getting money for his mom's bills) also only got mentioned again a few...