I've had several experiences right now... especially during second and last boss fights... where the power regeneration seems to be as if it were set like a boss fight during an elite alert with no controller present to provide power healing (whether direct or via POT). This has happened during StU "Normal."
I have the same issue and it started happening after the last server maintenance. Our stats got messed up but I only seem to have power issues in Raising Hades.
