So with my friend, we have been playing competitive match recently and we have had a recurrent issue.
When one of us crashes during the match, he cannot join the game again.
What happens is exactly that 
- game crash for one of us
- relaunch of the game
- game says : “Bla bla you left a match, do you want to re join it ?” we say yes
- game then says : “Do you want to leave your party ?”
- from then, 2 choices : “exit” or “ok”
Exit leads to exiting the game and then not being able to join the ongoing match.
Ok leads to another pop-up box saying that it is impossible to join the match.
Great.
And then we get a competitive cooldown.
Great.
Please have a look at the issue for the next update, it’s really annoying and leaves the team in 4v5.