m0useanswered grow question 6 months ago Looks like it could be from heat or overwatering causing root issues when it was growing. Or maybe the RH is out of wack. but I feel it would be somewhat in rage with your pots medium not being bone dry. Your diary says RH is 30%, could try getting that up to aorund 40-50% and see if it helps. Temps and PH seem on point. If you have not been overwatering it I'd say RH is the main cause.
Good Luck!