If you have been playing Trials of Osiris before unlocking the Elimination card, the grimoire has been accumulating points from those 'round win tiers' in the background. The grimoire score in game has been counting those points, but the points haven't shown in some other spots (like destinytracker.com) because the main card was still locked. If you already had 100 round wins before unlocking the Elimination card, the grimoire in game would only go up by 5. Looking at the cards you're missing on destinytracker, they total up to 45 points for xbox available ones. So 3575 plus those 45 would put you at the current xbox max of 3620.