what is the soil mix that ur using. if coco its calcium and magnesium. Manganese is not as common as cal/mag. plus autoflowers love them some cal/mag. mix dolomite lime at 1/4 tsp per L and foliar. that will help with the magnesium issue. the calcium issue however is going to have to be combated at the root zone. Calcium is immobile and has to be taken thru the roots. because you have what I believe to be both, with a possible K lock out you need to flush, I would flush with epsom salts in the PH adjusted water. and dont feed anything. PH adjust your water after adding the salts.
alot of people will say to feed 1/4 strength but in my experience it works best to overcome the PH imbalance first. thats what lock out nutes in the first place. Then in the absence of fertile soil the plant will start to take from its carbolhydrate and nutrient reserves in its leaves. N will be one of the more prevelantly needed compounds. so you will start to see slight yellowing when her hunger or vigor returns. When you see this then feed at 1/4 strength as the plant has a hunger for food. The next watering feed at 1/2 strength and she will be right back on track within 1- week or 2 at the most. this is provided you fix and remain at a fixed PH.