It's actually twice they did it.
The first week of promotions (Episode 204) is the one that blew up, with Everglow winning by eleven points, and the Chinese fan doing the calculations to suggest that DC should have won, even if the "expert" judges gave them zero marks.
The second week (Episode 205), the Show aired, but there was no pre-voting or live voting, and no winner was declared. It was stated that this was because it was a music festival special, but apparently (I'm relatively new to all this), usually winners are still normally announced at these events.
The third week (this Tuesday, Episode 206), Dreamcatcher came first in the pre-voting (Oneus were a fairly close second, everyone else was leagues behind when I checked). But when InSomnia logged in to vote for them in the live show... they hadn't even been nominated. The guy who won (Jeong Sewoon) actually came fourth in the pre-voting.