I was playing on the DE server in vanilla1 and the room was filled with about 20 people or so. The amount of players decreased over time until there were 7 players. I clicked the room list and it showed that vanilla1 had around 20 people. I clicked it and got transferred to a second room which was called vanilla1 with about 20 players.
I thought that my mind tricked me or something, so I whispered to a person that was in the first room to confirm that it was vanilla1 and how many people there are in that room. She told me that she is indeed in room vanilla1 with 5 players, while at the same time I was in vanilla1 with 20 players.

In summary:
There were 2 rooms with the same room name, one of them showed in the room list, the other didn't. People kept leaving the one that didn't show on the roomlist so the amount of players decreased over time.
I assume the first room somehow disconnected, I'm not even sure if stats counted during that time.

It's a split in the satellite servers; it's been fixed like four times but it keeps cropping up zzz

This bug has happened over three times with me, and it's caused lots of problems when I try to meet up with friends in specific rooms.