My guess is that it is somehow a reaction of the capacity for BG Dark Blessing to give negative saves if CHA is negative and the way Loremaster feat secrets are done. It would take looking under the hood of the two class' interaction to know.
Since there are free relevels for the next 13 days or so, I would try releveling and see if the problem persists. That and remake the character fresh on PGCC and see if the problem persists.
These things could fix the problem or they could help whatever member of the team gets time to take a look in figuring out what is going on.