Hi there, basically, yes, you have burn from adding the root juice, which is actually a dangerous thing because it raises the pH of the soil, so you have so called "pH fluctuation" which is causing these sorts of problems. Probably the concentration is too high and the pH is too high. If I can also say one thing : the lamp to plant distance should be less : try 30 CM so you can control the stretch from the seedling. So i would just start again because it's quick and you can avoid these problems and have a perfect grow, but if you cant start again i would suggest to pH the incoming feed, and follow a strict feed water water feed water water feed water water schedule. Dont feed every time and dont feed much above pH 6.0 ... for now you should water with plain water until the plant is ready to be transplanted. I hope this helps ! 🚀