Great idea for a new series! Nursery tip: potting-up plants, shake the pot vigorously after placing the plant and the loose soil to allow the soil to fill in around the root ball. Then center and level the root ball and snug the soil in around it.
This happened to me too with my young Jaboticaba. I assumes it was due to some stress. I was afraid to repot and cut any roots in order not to cause any more stress. nothing happened for a few months. then I decided to put it in the ground. After a month it started to leaf out again. it is still a little bit stunted (maybe because of winter). I hope for the best for to both of us.
This plant hadn't been fertilized for awhile, and it had regular water. The only thing that had changed in its world seems to have been the sulfur spray.