@OneDominator You're meaning that the game doesn't fully fill out your team.
This sadly can happen in any gamemode and I think its caused by the game starting even though some players didn't load into the match. Since they never loaded in and the game was started, it doesn't fill out the teams unless its Mixtape.
This might be either from players getting kicked back to the lobby by the game or by simply not getting put into the match, (where the game says "matchmaking", then it goes to transfer the players to the match, only to keep them in the lobby).
There have been times where me and my friends were in the lobby and we were waiting for the match to start. Next thing I knew, I heard the sound of the match starting, and then both of my teammates grayed out and it said they were both in a match, while it kept me in the lobby.
There also been times when I was solo queing and I hear the match was starting, yet the game left me in the lobby. I would imagine that whatever team I would of had, it was either a solo or a duo squad due to the game keeping me in the lobby.