Also 2 of 4 plants have some of these leaves on them. Other 2 plants are starting to show dark spot near the center ridge of fan leaves.
nutrient burn is generally on the tips of a lot of the leaves while your leaves show more of a calcium def to me. I had this issue with one of my rooms and had to lightly flush them then supplement with calmag after and it went away. But you said it got worse from calmag so I dont want to steer you wrong. Maybe try a flush with good ph water. I am curious what others may think.
TBH I THINK YOUR LIGHT IS TO STRONG FOR THIS STAGE OF THE PLANT OR TO CLOSE THATS WHY ITS CURLING AND HAS LIGHT SIGNS OF NUTRIENT BURN Sent from my SM-G950U using Grasscity Forum mobile app