Sick Pineapple Express

I planted this Pineapple Express autoflower around 12 days ago. At first, growth seemed healthy. Then a week after being planted, the first set of real leaves started yellowing from the inside out. As the plant has continued growing, its new growth is pale yellow and very thin. Any ideas what this could be and how to fix it?

I had basically the same issue. Definitely caused by some kind of environmental stress (soil, water, heat, light, etc). I can recommend what I did, because it worked for me. You need to remove the seedling as if transplanting it, then prune about a third of the roots off and repot. Water very lightly and let it rest for a day or two with indirect light. Should bounce back in about 2 days. To me, it was worth a shot, I had three seedlings that had the same issue and they are now regrowing and getting dark green leaves again. Hey, it's your call, but if I were you, that's exactly what I would do. Good luck

Here you van see them recovering with green coming back.

Also water the soil, not the plant. Keep them leaves dryer

Looks like light burn.

What lighting are you using, and how far away from the plant is it?