Need more help yellow leaves

Hello guys. I am finding out I suck at growing. I have been having issues with one of my plants. The leaves were getting yellow. It was suggested to transplant them from solo cups to bigger pots. I used 1 gallon. The leaves went back green and looked good for a couple of days. Now it’s back to yellow and worse than before. Any help would be appreciated. I have another plant exact same everything and it’s fine

3x4x6 grow tent.
1200 w led and 2 600w led
Humidifier which is kept around 60%
Soil base
Lights at 12 inches or so

If you need anymore info please ask. Thank you again guys.


Had to go back to your original post, to confirm my thoughts.

Those leaves were touching your soil, and in a nutshell, your leaves soaked up so much nutes, it killed itself.

Looking fine, keep at it. Trust you will have plenty of leaves soon enough.