When I try to join a Gambit game while in a fireteam, I'm sometimes disconnected from the game while on the loading screen and kicked from the fireteam (hapens around 50% of the time). I have no issues while already in-game, and have no issues of the kind when connecting to Crucible, Strikes or Raids, nor when I am playing Gambit on my own. When I'm not the fireteam leader, I also usually have no problems in reentering the fireteam and connecting to the Gambit game in progress, albeit quite late. That said, It does penalize me for leaving a Gambit game in progress, meaning that I can't launch Gambit games by myself later on. I play on PC and a have a good and stable internet connection.