When you want to click on a monster and an item is underneath it, you click on the item instead of the monster.

I think that your click was slightly off the monster and triggered ground items. Usually, npcs and players have priority over items on the ground. When using the vbomode, the monster's clicking area becomes exactly its model. If you click between the dark beast's feet, you will click on the ground.

Ah okay, thank you for the explanation

Thanks for the bug report nonetheless! I'll see if I can improve the system.