It’s happened on this game, too - you can see in chat: Ladder Challenge: Gooplet(#3) vs AlejandroDaz(#3)
I think it may have actually happened before and I just didn’t notice. In each occasion, I was able to challenge the person directly below me in the ladder, which normally isn’t possible, since they shared a ladder ranking with me.
What’s the deal with 3a/3b? What could cause that kind of ranking?