We identified a bug preventing Circle of Healing and Wild Growth from being able to find targets in Vortex. It was not our intent that these heals be prevented during Vortex (beyond the nerf we already made to prevent them from being spammed).
We should be able to fix this in the next couple of days. (Source)
I usually pre-HoT (Regrowth and Rejuv, depending on raid size) to heal through Vortex, but we had a couple of deaths in 10 man last night just from people ticking down and not really being able to do anything about it when Swiftmend is on cooldown. Being able to toss one Wild Growth again will make a big difference.