Same issue here, Dragon's Bane, Dungeon Master, and Would you look at it achievements not working. Submitted a support ticket and reported the issue to Xbox. They really need to fix this for those who have put in the time to unlock them.
I think Rogue needs to be fixed in PVP as well. If they have stealth they shouldn't be able to deal so much damage, or they should not be able to dodge every attack thrown at them. Fix either one and shouldn't be a problem. **Character is out of balance to the rest or you wouldn't see so many people using them in PVP.