[GAMEPLAY] Match history incomplete (missing games)

Not all games I played show on the official match history (http://matchhistory.euw.leagueoflegends.com/) but they show up on lolking.net (and they took place!). I can't imagine what is the cause of the bug and cannot reproduce it. I attach pictures of both official and lolking partial history to show the difference. All games - missing or not - were either blind or draft pick in summoner's rift, not ranked games. Only correlation may be that I used Orianna as a champion, but she shows up once...