Hard to tell with limited/no specific info. Looks like overwatering to me. How often are u feeding/watering? Soil or hydro?
what is your water and feeding schedule? Temps? Rh? Soil? Light source? Ph? Nutrients used and additives? Bla bla blaIdk what this is and some of the other leaves that are green are scrunched and rough and ridged any info will help
How often are u watering? Are u letting the dirt dry out in between waterings? Also, have u checked yr runoff ph/ppm?Water feed water is the schedule room temps don't exceed 78 ppm haven't exceeded 400 on these yet using botanicare watering at ph 6.5 all grown in Royal gold tupur