Everything works this time actually, it got fixed with past maintenance. Quest item percentage bonus works for all the quest.
For example the item for valeria vendetta normally is 50% drop chance, now is 100%:
Kind of salty because i had to use warp free item last weekend to hurry on quest, because it was not working, but it was an event one for 3 days anyway.
Edit: warp free works now too, it asks to pay 0 feso