I checked in known issues. This issue isn't there. I was surprised that I couldn't find that any reports of this (I checked, but I've been known to miss things).
The heals on these units seem bugged. I tested in campaign and also on custom battle map against AI.
In campaign, I didn't notice any heals happening at all. In the custom battle, damaged units brought into the healing auras heal for just a short time, for a small amount of HP, and then stop healing.
1) Are the heals supposed to function this way (I doubt it)?
2) Can someone load up a custom battle and confirm?