Sovi helped me with dg masteries on an alt so I could make sure it would unlock the 2nd mastery tab. On the 3rd quest where the character has to solo the boss of the one dungeon on hard mode, I took my character in to set levels. After I came back out, Sovi went in to clear the dungeon. When she came out, I tried to enter and it asked me to set the difficulty. We had to do the process a second time. It worked that time.