i've noticed that when i try to do regional quest in Basilisk Den

The Reward of the regional quest that is usually in top right never shows up in the main spot

so i tried to find it and ended up finding it outside the temple / cave on the left side

.

if you are inside the temple make sure you go out and check how many mobs have you killed before back grinding, you might have finished it without knowing it since the reward option didn't show up inside the main spot.

Good luck.