In a 3 player game on the same internet connection, 2 players exited on a disconnect.
The third player remained in game and the other 2 players were able to join back in.
This seems like a game issue rather than an internet issue.
It happens once every few hours.
On a game disconnect at character level = 4, the char. level went back to 1.
After exiting Diablo2 and hitting play, the game wouldn’t start correctly.
After exiting Battle net and restarting, the character level was back to 4.