Darn. I hope this doesn't mean I have to restart my progress to get it to work properly. ^^;
SPOILER warning in case;
I'm currently at Level 30, With 16/17 total events, and 11/12 nightmares. My normal achievement list is filled with just "Zealot In Training" and "Intermediary", whilst my Gallery Achievements is all still "incomplete" despite multiple times I've done them according to what they detail.
I'll try resetting my progress, and if that doesn't work oh well I guess on my part. XD