Calcium or potassium deficiency, might've had a lockout from you pH problem if I remember correctly. If you got it under control, continue on regular feeding schedule. Do not overfeed 👍🤞👊
I’ve read how you do the soil in your diary and I think you have done it wrong.
Is too much coco, so you have to deal with a coco substrate , i think is a calmag def due to this factor ( the 70% coco substate) .