My Hoya Bella Anneke Buis, otherwise known as Hoya Bella Albomarginata looks pretty healthy from this picture, but has been dropping quite a few leaves for some time. Many leaves started to get shriveled looking, which is a sure sign off root rot. I took it out of the pot, and sure enough that was what was going on. I lose very few plants to root rot these days, but sadly this was one of them. Here is a photo before I chopped it up into cuttings to restart it.