Did you transplant the and then nutrient them? That looks a bit Iike “the claw”. Happens when you over nutrient. I use a lot of silica to prevent this I my transplants and it helps the plants for cloning as well! I don’t double up but I do, every other feeding or so , give them RAW silica full strength and the general hydroponics.... amor si. Almost couldn’t think it up but these work great at helping to prevent damage and disease by building plant structure! Hope this helps!!