Why can't I save at the end of my Kingdom Hearts 2 game?

Alright, so here's my problem: I have finished my Kngdom Hearts 2 game and I have defeated Xemnas for the final time, but I cannot save after I have finished. After I defeat Xemnas for the final time, my screen shows a drawn picture of Sora and tells me my stats. (e.g. Number of kills, number of deaths, etc.) However, it simply stays there and I cannot save. I have left my PS2 on for hours to see if maybe the screen would eventually change and I have tried everything to try and save my progress of gameplay. After I eventually turned my PS2 off later that day, when I powered it up again to play on Proud Mode, I was at my last sae point- Right before I fought Xemnas. I am very confused as to why I cannot save my game at the end. Someone please help. Any input is welcomed.