This issue most likely happened due to the following -
1) First click "select" next to a game,
2) and then "update home players", and "update away players" and put players on the team. Click "save" on these screens and notice that the players now populate in the list below the game details.
3) Then change the date and click "save changes" button.
Doing this will cause the system to correctly assume that "oh players have been added, therefore this game has been played". Then when the game date is updated and "save changes" is clicked it counts up the stats (which is 0 because they didn't enter stats). So the score becomes 0-0.
You just need to not update any home or away players before they save the game date. OR if the game was never played, just click "delete" next to the game - don't try to edit the game date.