Why do games get cancelled in chess variants?

I love chess variants some being slightly more fun to play than normal chess. Usually I play a fun game like I wanted to, but I noticed when I join chess games, before the first move, the game gets cancelled! And sometimes the player resigns after a very few moves, which I get very confused about. Is there a reason or can anyone explain why my games might get cancelled? 

Your opponents might resign after a few moves because they had accidentally clicked on the game variant. There are loads of them, so this could be possible. As for the games getting cancelled, I can find only two reasonable explanations until now- They are aborting the game. Someone has bad internet connection. So yeah, if those aren't the problems, I don't know what is. I'll certainly try to help you, though.

Uu