What ph is your input? I’m no expert but I would thought if it was to do with light all the top leaves would suffer including the auto, I would recalibrate your ph pen and maybe reset with a flush
@pazman, Could be Cal-Mag, but could also not be. And just worth the PH. I know everyone always thinks it's Cal-Mag, but they just ask themselves whether it's the fertilization or the processing. Everyone knows that, Cal-Mag is the sign but usually not the problem.
Nice nice , Doesn't look exactly unproblematic. I also have two royal dwarves and both are treated identically. One looks like yours and has more hanging leaves, but hardly any definition. The other one looks perfect. I haven't really figured out why they're so different yet. Hihi, one of mine always looks like she's dying and only looks healthy for 12 hours out of 18 hours ligth :) the other one manages well for 16 hours light.