Ok, Francesc. I seem to have missunderstood you on the previous one.
The message is not new, it has been there since the first day. There is a issue with Google Forms not displaying a message when someone sends a vote to the same game triplet before you. The form simply reloads with three diferent games, as you cannot vote to the same triplet that has already been voted.
Sorry to here that, but that's correct. If you didn't see this message before, you haven't voted until today. You were unlucky enough to collide with other voters and send your votes later than them.
Of course, this issue is a problem we will have to look for on future revisions. For now, we can only feel sorry and assume that this doesn't work the way we would like to. Sorry about that.