From the rules "If a character starts crossing to the next terrain grid and the squad is at the same location, they will move with him. However, if they are not at the same location as the player, they will cease to follow the player. "
Its linked as 'Report Bug' at the bottom of the sidebar. Its a separate thing where the devs keep track of bugs that crop up with the game so they can easily identify them and fix them. You will need to make a new account there (its not synced with your SWC account), so do that first using your SWC handle.