The game auto saves about every fifteen minutes, at a guess. If you had been on for much less than that and hasn't saved your character may be lost. I thought that the game quit you out after a bit, meaning you have effectively saved and can come back later.

However, when in the middle of a role update I'm not sure if you can save or quit, so that might have prevented you from reconnecting. It is the only time it's happened to me. I lost connection while in the middle of writing my role and my character had to be restored from some time ago m. Best plan is to just start a new one. Re use the role if needed.