New growth is looking mutated, why?

Yes i think you're going just slightly too heavy on the nutrients. Make sure you use just water every 2 or 3 feeds 👍🌱💦

They look like they have enough nitrogen for the rest of theirs life ;))) Slow down, leaf colour won't return to normal, but overfed is not so active in photosynthesis as under fed !!! Less is more ! Don't cut n feed totally, but reduce to 25% or so ... All the Best !

Too much N ,your leaves starting or are claving already .Less N in next feed.

If you link your diary more people can give you a better idea of whats happening. A lot of people will not bother to go into your profile and find it. The tips are yellowing a bit I see and the leaves are crazy dark. Maybe to much feed. Some of the leaves have a downward point to them as well on the pinnacles. Also a sign of to much nitrogen. Don't know the brand your feed or its ratios. Give it a check to ensure your NPK is inline and not to high. If you are using a truly 600w grow light 20" from canopy I'm guessing that might be it. The manufacture recommends to hang it 24-36 inches from the crop. Best of Luck and Happy Growing.