The diary says 5 weeks, you have nutrient burn and this plant in particular might be a phenotype more inclined to the photoperiodic side.
Stop using nutes for the next 3 waterings, DON'T flush it, and keep her schedules on point, if you have a timer try to check if its not failing somehow giving it a 1h of dark midway thru the light hours, if everything is properly done and you still don't see any tips of pistils starting to come thru next week, try to switch it to 12/12 and it should work.