I was playing a live game with my opponent when a notification about a new move in a correspondence game popped up (black circle notification), so I clicked it, made a move and returned to the live game only to discover that it was automatically resigned.
If you leave a live game, a timer starts for 2 minutes, if you do not return to that live game before that timer runs out then the game is resigned for you. You can open the other games in a new tab and your game will not be resigned.
