Not sure if this is the place to post this, but I figured I'd share.
Every time I fight a Zealot, they seem to just randomly regenerate health in combat, while actively engaged in combat (i'd be dodging or backing off because of a flash bomb). They fully regenerate both their health and shields, this happened multiple times. Second Zealot this has happened to while fighting.
I found a reddit post describing this exact issue with multiple other players having the same issue. One player said he resolved it by keeping the boss poisoned the entire fight (I however don't have the ability to poison enemies yet.)