Starting around Lv50, some of the enemies on the regular maps start hiding under ground, and you need to step into their vicinity in order to make them spawn and appear. Putting aside the 'detection range and sensitivity issue' of these mobs, where sometimes they still refuse to spawn despite the players standing right on top of them, this is extremely slow and annoying, especially in special mini-regions that do not have 'dungeons' and thus in order to increase fame. You need to do repeatable quests that often have to kill said 'mobs hidden underground', and they are very time consuming even compared to other more tedious repeatable quests.
The 'hidden' mobs that ambush players in the dungeons could stay hidden for all I care, but if its possible to make regular mobs stop hiding underground, can that that please be changed? Thank you.