AsNoriuanswered grow question a year ago My guess - ph off, calcium deficiency, nute uptake problems.
From look its coco and you water not enough, plus low humidity.
Thats how picture look to me
Rare i say this, but only because its auto, new seeds would bring better harvest if in both cases you do no more mistakes. Those plants wont get big, maybe not smart to push them even ...
Sorry. Thats my one of few such advices ever ...