Sorry I wrote a big long textbook on why it's sulfur then I deleted it by accident and couldn't be fcuked writing it all back put. So all you get is sulfur deficiency.
Try not to add sulfur after the 3rd week of flower. Sulfur helps with terpene production because it's a key element in building the isopentenyl diphosphate (IPP) precursors and is required for activating the enzymes that convert IPP into terpenes. Everyone rages about PK but the real key to next-level flower is sulfur. Just don't add it after week 3 as it can have negative effects on flower smell, taste Yada Yada. 😋