Act 3 - Bubbling Respite Bug

I have a quest item stuck in my inventory that cannot be removed, here are the steps to reproduce and what I attempted:

-I picked up Red Mushroom and Green Mushroom in Apex of Filth.
-I finished Act 3 and proceeded to Act 1 Cruel.
-Right after arriving at The Riverbank, I discarded Red Mushroom and Green Mushroom from my inventory. (dragged items out of my inventory, no notification appeared. The items did not appear on the ground, they were just gone from the inventory.)
-After arriving at Mud Burrow, I went back to Act 3 Apex of Filth.
-I picked up Blue Mushroom.
-I went to the Cauldron and clicked it, animation played and character had a voice line.
-Nothing happened after the animation, blue mushroom is still in the inventory.
-After re-entering the zone, the cauldron is no longer interactable.
-I tried to farm for the other mushrooms, that I had discarded, again but unsuccessfully.
-I tried to discard and to stash the Blue Mushroom, but I can't.

Now I am left not knowing if I have finished the quest, if I can still finish it, or if I soft locked it by discarding the two mushroom at The Riverbank. I assume me being able to discard the items in The Riverbank was no intentional behavior.

If possible, it would be cool to remove the Blue Mushroom from my character, or add the other two mushrooms and reset the quest condition so that I can remove the clutter from my inventory, thanks :) It happened on my character named "LuDeRu."

Edit: I was able to remove the Blue Mushroom from my inventory. I think it was only not possible in down. But it was droppable outside of it. So there is no need for intervention but maybe the drop behavior at The Riverbank is still interesting to look at. And it is still unknown if I finished the quest or not, I don't know what should have happened or if I am now missing something.