Im having same issue but with an older plant, new growth looks good! But i noticed it last night so this am, i gave some nutrients hombults Golden tree, 3ml. just started yellowing pretty good this afternoon. Just at bottom.. Is she hungry??!!?! I usually give her an aloe vera soil drench once a week and then humboldts 2 times a week. Any help would be great. So Sorry for hijacking your tread but he seems to know a lot.By the time the plant goes into full flower, those leaves will become lowers and they will just end up falling off and dying anyways....as long as the new growth is looking nice and green and no problems are spreading throughout the plant. I would not worry at all.
Thank you!Its just natural die off, no worries..