Problem with three plants

I have eight plants this year. At this moment I grow them indoors on 30x30 cm with a 60W LED Panel.

At this moment they are in small 0,25l pots with light mix ground. They are 4 months old now.

Most of them look fine. But I have problems with my peppapeach stripey, it’s getting yellow leaves.

Also the leaves of my Aji Panca Lima are curling upwards.

My app says inside the box is 250 mymol/m^2/s, the light is turned on 18h/day and the temperature is around 28 Celsius.

What would you do?