Looking at the front EinStein page, everyone's listed as a winner of the Jan MC. Looking at the MC page, it appears that there was never a round 2. Has such behaviour ever been seen before?

hehe, yes it has.

Sometimes, a round does not start immediately after the previous is finished.

As a (nice) side-effect, during the few minutes (or hours) between, the contestants for the next round are all shown as winners.

It will be fixed as soon as the new round starts.

11 hours long we were all Champions of the first round of January. Nice. :-)) Please don´t fix it. ;—)))