edge of one of the leaves facing up

Your leaving are doing something called tacoing. They do this from excess temps and to much light, lack of air flow can compound this and underwatering. It's a plant defence to these stressors. Your medium in the pictures is looking bone dry. Your day time temps are high but cannabis can tolerate it with good fresh air exchange, if the air is stagnate and not getting moved aorund you want to lower them temps or move the air. Your night time temps are also high, I'd like to see them lower aorund 20-24c but if you can't lower it, it's ok. just have to keep up with watering. Your RH at 60% is not bad, and with the high temps it means plants are going to transpiration more, meaning they need more water with a lower concentration of feed in them or they will burn. High feed concentration + transpiration = burnt tips and leaves. I think you doing well so far, control the factors that are within your reach, water and air flow, temps can be a bit harder to control without getting more expensive equipment. Good Luck!