promlem

That is what is called tacoing due to too much heat. Also you are just starting to show potassium deficiency as well. Easy on the nitrogen you are at a more the sufficient level. So your light is too close or your grow area is getting too hot overall. 82f is what I max mine at. Summer it becomes a challenge. If in vegging you don't need super intense light. Leaves will stand on end in a praying fashion as new one grow if you have light in the sweet spot. Much healthier for plant and later flower development. Good luck and happy growing 🌱

In my opinion, the problem is either thrips or too much heat and little air circulation..... do you grow indoors or outdoors? Because in the latter case, it's impossible for there to be poor air circulation and high temperatures; the plants, even if they are at 40 degrees outside, respond very well!.... I think they are THRIPS!!! CHECK UNDER THE LEAVES FOR INSECTS; THEY ARE REALLY TINY AND LOOK LIKE LITTLE WHITE OR BROWN DOTS.

This is heat stress.... your lights are MUCH too close to your plants ... back them off to 18-24" and she should be MUCH happier. This will also get them to grow taller as they reach for the light! Right now, they're probably trying to get away from it. Good luck!