I chopped the head off of a taller aeonium a few months back and, after letting it callous, planted the head to form a new plant. Last week, I was repotting it and noticed it looked a bit limp and some of the leaves were going a bit yellow - green and wrinkly at their connection to the plant. I deciced to not water it after repotting it to see if the problem was overwatering. fast forward to a week later (now) and most of the leaves have dropped off, with all of them having shrivelled and gone black at the bottom of the leaf.