Growing Hoya leucantha Part Five

All of the cuttings that I took of my failed plant easily rooted, and I was able to share this plant pretty widely through sales on eBay. Now here is the odd thing, since starting this plant over, twice more I have ended up with spectacular specimen plants that inexplicably failed with tons of leaves that would yellow and drop off. Each time there was no root rot observed at all so I am pretty baffled as to what the issue is. I have never observed another Hoya that would drop leaves without having compromised roots. Other than this problem, it is a stellar plant.