iirc the actual suspected cause according to kagura's mod team is too many drops(~30) at once. So it's not explosions itself but a lot of enemies dying at once...which is a kinda major issue to have. So yeah piercing arrows are likely much safer but there's still a possibility and if u use certain characters ultimates it might also be an issue.
Anyone has this bug where the Souffle event "machine sex and human sex" just doesn't go away?
Meaning even if you click and see it, that event still sticks around no matter how many times you see it