I’m running a Rogue with 8 points in Thiefguard, which grants “+48 Health Gain on Glancing Blow”. I have >100% Glancing Blow. Thiefguard’s Health Gain is not proccing due to Titan Heart, but Titan Heart say “you do not regenerate health”, and health gain and health regen are different, right? Titanheart shouldn’t stop health gain.
Replacing Titanheart with any other armor removes this issue, so I know it must be Titanheart.
I also tested it by putting on Last Steps of the Living (which reduces HP to give Ward), and HP was not moving at all when I got hit.