after some testing i see why this happens. its seems like after you have 5 barriers your shots are unblockable but you get like a ghost positive pasive because you trigger myst-match and standout pasive so for example i have 5 barriers and i am against standout and i do a shot if standout pasive...
when i was fighting in holodeck hazards i was matched against a myst-match and because she is water element same as corrosive agent she gets barriers, but the problem is when i got 5 barriers as corrosive agent every time i did an unblockable shot she gains 3 barriers idk if having prestige...