It was confirmed that Race 12 wasn't being played in 4v6 due to disconnections.
(Here is Rule 3.3.3.d: d. Races that begin with a 2-player differential (see 3.3.1. f.) between teams due to disconnections will not count. The room must be closed and reopened, with the team that was short on players waiting 30 seconds after the room is reopened for the opponent to join.)