Hmm, well, I know I completed the tasks before 12am/0:00 in case they reset then (this was before I knew they reset at 5am). The only thing I was doing past midnight was hotsprings, and then using the stamina. I do have the jonin medal so I was automatically checked off for the next day's sign in. It's possible that had something to do with all of the tasks not resetting I guess.

However, a group mate who does not have the jonin medal is also having the issue of the tasks/event not resetting, and they didn't do the sign in for today until this morning around 10am server time, so it was after the 5am reset.

So far the only thing I can think of is that being online in the game after 12am/0:00 (regardless of having a jonin medal or not, the auto sign in might not matter in this case), is making the event bug out. The two other group mates that are having this issue as well were logged in past that time, but everything else regarding dailies or tasks for the event were done before midnight.

Of those saying they are having the same issue, do you recall if you were online after midnight?

Well, that's lame and a bit frustrating. Guess I'll just make sure to be offline 12am-5am for the rest of the week. =/