Are you feeding every pot by hand or are you on auto feed system? What are your habits.
This could easily be micro climate, soil too wet, cold soil, all sorts of stuff. And if your not skipping feeds and labeling each one on their own needs, you probably just have a sick plant and need to cut nutrients down and the lights.
But it looks like you are on a mass grow so I bet you wouldn’t be babysitting each plant. Mixing up buckets just for her and her and her.
This is going to be a personal adventure to figure out and you might find a new process of monitoring each plant.
Unless we get all the missing information down to the T, it’s going to be difficult for anyone to point out a specific deficiency or fix. Reason is because nutrients determine the light the plant can handle. If she is having trouble uptaking, she won’t perform the same as your others. No matter if you’re feeding to a T or not, she is sick and the light is too much for her to recover or she is in a pocket. Never know unless we know it all. Nutrients are not everything and sometimes light changes fixes everything.
look I baby my plants and no plant is the same. They want more or less sometimes and I have 2 plants that suffered more issues during growth. They don’t want as much water for multiple reasons including where they are located in the room, air circulation, micro climate, position to the light…all that causes them to need less and so I have to give it to them or they would be pissed off. You have some upset plants and reductions always work to fix problems. We never want to and we want to keep pushing them, but some plants just want less.