This bug is caused by a value for the Talent_Unstable skill, "Damage", not being set to "SourceMaximumVitality" in the Skills Data file. Setting that value causes the talent to work as intended. I have posted a bugfix on Steam Workshop, and I can walk people through the fix if they want to do it themselves using StatsEditor.

Last edited by ZiggyZeitgeist; 20/09/17 08:07 PM. Reason: Said feat instead of talent because I play too much D&D :)