@FlorentDubois, I can confirm that the last available level on Facebook and mobile is 2605! However, the Studio are having a test at the moment were a group of players gets access to the next episode (in order to ensure there are no bugs and it's completely random) and this is what you are seeing on the Episode Race feature.
I've passed on the feedback that you're game is being matched with player who are part of the pre release test.