I am currently in act 3 and for the second time have broken my oath.
Unlike the first time when I was able to play 1k gold for atonement, the Oathbreaker will not show up in camp leaving me unable to atone or change my class. I have attempted to set up camp in different areas, closed and restarted the game, etc.
At the same time, Volo is also missing.
I have submitted a bug report for the oathbreaker issue and there are numerous Reddit and Steam discussions reporting the same issue. Hopefully this can be resolved soon.