Hi
@Andre3001 the substrate is soaked, the roots do not breathe and do not develop, the growth of the plant blocks and begins to yellow and burn the leaves. let the substrate dry well between each watering, control this by the weight of the pot, the substrate when it is dry is very light. the humidity of your grow is very low, the ideal at this stage is 70% -80% RH. good luck mate 🙏👍