There is a mismatch between what /reputation shows and my badge tracker for 'epic':
days represented 1269 rep cap was reached via rep from upvotes *only* on 42 days earned at least 200 reputation on 45 days earned 36 reputation from suggested edits
Meanwhile, the next badge tracker for epic shows 44/50:
This appears to be caused by a user who had voted on a post of mine that was deleted (I saw a 'deleted user -10' show up in my rep history a bit ago).
So, in /reputation, it shows:
-- 2016-02-10 rep +200 = 47281 -- 2016-02-11 rep +215 = 47496
while the reputation log on the site shows:
The reason that I'm a bit below 200 was that I down voted several answers at 22:27.
However, the reputation (and thus badge tracking) hasn't caught up with the reputation that wasn't assigned after the deleted user's vote was removed.
You can see 21:34 down vote rep getting that rep 'back' with the 21:40 upvote (limited to +1 because of the rep cap).
However, the 22:27 down votes weren't 'recovered" with the 22:39 up vote to reset it back to 200 rep cap for the day, and thus a mismatch between the reputation cap information on /reputation and displayed for the epic badge tracking. I believe that this is from a user being deleted who had upvoted a post that day, and the removal process isn't properly recalculating the reputation for the purposes of badge tracking.
I will note the possibility that I've confused all of this and /reputation and the epic badge tracker are looking different things, but if that is the case, then there's still a bug (just that this isn't the underlying cause).