Nutrient burn

Looks like just a hint of burn. Are you monitoring the EC of the feed solution?

Pot is rather small for the size of the plant also.

Yellowing/early lime of the areas between the veins (interveinal chlorosis) is usually indicative of manganese, iron or magnesium deficiency. Iron deficiency affects the youngest leaves first, whereas the symptoms of manganese and magnesium deficiency tend to start in the older leaves. Guess based on visuals queue only. No other apparent symptoms noticed. Excess of elements such as manganese in the soil can interfere with plant iron uptake triggering iron deficiency. Iron is needed to produce chlorophyll, hence its deficiency causes chlorosis. Or it could just be plain iron deficiency. Cause and effect. The concentration of iron is too low in the root environment. The root temperature is low. The root medium is too wet, causing the oxygen supply in the roots to stagnate. The root system functions inefficiently due to damaged, infected or dead roots. Best I can do without diary, good luck.