Philhsyanswered grow question 21d ago This looks more like a genetic mutation or early stress issue than a virus. Possible causes are unstable genetics, pH/root zone problems, or a micronutrient imbalance. Since the sister plant looks normal, it’s likely specific to this phenotype.
Keep pH and watering stable, avoid overfeeding, and use light CalMag if using soft/RO water. If new growth improves over the next weeks, it should still grow fine.