City square monsters spawn outside of playable area

full cleared the map, and yet there's somehow 50+ monsters remaining, i then in the corner of the map i see a metamorph icon, across the water and outside of reach, i'm guessing there's multiple harbingers and atleast 7 metamorph monsters over there as i'm missing 7 organs.

please make it so mobs cant spawn outside of the area on the map CITY SQUARE