Your led light is too close. Modern LEDs are pretty powerful even though you may not feel much heat when you put your hand under them.
18 inches is the closest I can go with my blurple lights and I keep my quantum boards about 30 to 36 inches away from the plants. Every light is different and some plants are more sensitive. Safest approach is lift the lights a good distance away and only put them closer if you are getting too much stretch in your node spacing. Good luck!