As reported on another topic, the problem of being sent to US server instead of the preferred server is still happening.
I was affected by it today (June 17) around 1:10 AM (UTC - 3). We were playing on Brazil server before this game and all party members had Brazil selected as Preferred server. Since we were on a party of 5, we left the game to avoid suffering due to high ping.
This is a really old bug, as shown on this thread below.