Might be nute burn. What are you feeding them in what medium?
I have been feeding them advanced nutes micro, grow and sensi cal in r/o water with a 6.2 ph in dakine coco coir lite 70/30 coco/perlite
If your using dakine soul you should pair it with dakine nutrients here’s my code for 20 percent off Chadly710 I’ve been growing monsters I never have to adjust ph and have 6 girls with the same feeding chart they reccomend and it’s been flawless
How often are you watering she could be just thirsty