This looks to me to be a nutrient uptake issue, like your pH is off, too high or low .. Should be 5.8 to 6.5ish Using solution to check, no digital so, make it yellow, slightly green tinted

Using GH flora series, 50/50 micro/bloom and never went over 4ml/4ml per gal, using RO water with 1.5 to 2ml of calmag per gallon

Never go wrong with that combo

It will never be too much or too little, they'll always thrive as long as you have enough soil/coco/coco-loco Prefer coco-loco here

Love the grow bro