If you are actually missing any games from your scorebook please let me know, but I suspect it just looks confusing because the dates listed in the scorebook are for the start of the game rather than the end. For live games it barely matters, but corr games the two dates could be weeks or months apart.
Listing them that way is the standard and actually makes the most sense in the long run. It's the order you would have the scoresheets in if you were keeping them by hand, plus it groups together games from the same tournament, or games from a match (where you play multiple games simultaneously against one opponent). In the short run however, it can be non-intuitive, particularly right after you finish a game and go directly to your scorebook. You might expect the game to be at the very top of the list since it just ended, but instead it's way down and maybe on a previous page. I'm not sure what the best solution is yet, maybe we can just label things more clearly, or maybe eventually we can have it sortable by your choice of start or end date.