AsNoriuanswered grow question 3y ago My guess. First they have too much N, could do trick.
Second you underwater them, all photos look like this. This could lead to proper salts build up ( hard to disolve ).
Third they look either hungry, either having root issue, both look very not possible tho ...
Forth wrong ph , sometimes even meter lies, are pots really light, or just top soil dries out ? That will give you answer.
Either lockout from wrong ph or N toxicity.
If they were heavy feeders and got used to, could ge hunger, but i give that 1%.
Run off ppm and ph would tell a lot in such case, just take samples right.