I'm not aware of a bug that causes enemies in the vanguard battles to attack over long distances. Can you describe it more detailed? Is the problem on every map? Is it by specific enemies? Have you done something in particular before it happens? Are the enemies over 3 tiles away? Have you loaded an auto-save or done anything else besides playing the battle normally?
How did you lose your saves? If you downloaded a new full game version, you need to copy&paste the entire content of the www/save folder, including the global file, or the game won't recognize your saves.