I am using Healbot Classic 184.108.40.206 Beta 2. It appears ever since the move over to LibHealComm-4.0, Druid's HoTs do not show up in heal prediction. This is on a fresh install of healbot after clearing out my WTF contents. I also downloaded Bugsack/BugGrabber, but no bugs appear when I cast rejuv or regrowth. I have also upgraded the LibHealComm-4.0 libs to the latest alpha version available, with no change, but I do not think this is a lib issue since heal prediction is working in ElvUI (it uses the same lib).
EDIT: With regular heals like Healing Touch, heal prediction seems to work. Just the HoTs not working atm.