Persistent Charge Bug
I don't think this has anything to do with the persistent charge, but a lot of problems are starting to come up ever since this type of bug began.
The only real persistent charge bug that I think bothers most people is the one with Nick Fury, but there are definitely others out there that are needed for certain champs.
I spoke a lot with my alliance mates and we've all said that at least a couple of times, when the persistent charge is down Parry doesn't work.
In order for it to come back you need to exit the game and wait up to an hour sometimes until it comes back.
Please dig into this persistent charge bug Kabam. Especially late in and things like AQ and aw where Parry is needed for certain fights.
Fix it. And fix it soon