the overwolrd event has a small chance of giving it and that works

the depths event is 100% but once per character and its rarer

a lot rarer

yea deepspindle is rare af

he founhd it in depths too but the guy wasnt there

the depths event was the same as overworld when he do it and there was no man there

there are 2 different events

one is the same as ow

the other is the one with the capra standing aside

both can spawn in the depths

yea theres either npc or the light

capra one is a lot rarer

so uhh not a bug!!!

Purple circle event on its own that spawn without an npc is the non-guaranteed version of the event that spawns a chest that has a chance to contain any of the three main items The spawn with an npc (a capra), with a purple circle next to them, is the event which guarantees all 3 items of the set (including deepspindle) on the first kill. You are just unlucky

Keep in mind the capra event is a LOT rarer