1st autoflower northerlights

Hey there Villa1! At the top left of your 2nd and 3rd images of week 5 I notice the leaves curling down as you described. If this is the area you are questioning this the beginning of a Nitrogen toxicity! If you look at the lower leaves you can see some Chlorosis(yelIowing) where the plant pulled nitrogen from the lower leaves to feed the new growth at the top. I would keep an close eye on the situation and it if gets worse you will want to flush the plant with pure PHed water for a few days before reapplying the same nutrients with less nitrogen in them. I hope this helps resolve your question @Villa, best of luck with grow. If you have any more questions feel free to ask 👊