So...about this portal business. I'm super confused. I just started playing about two hours ago (finally) and I'm in Traverse Town right after the Drop from Riku back to Sora, and my journal lists Sora's "Ending" Dive in the Game Records with a high score of 0. Is this going to create (significant) problems for me moving forward?
I understand your concern, as I didn't want my game to bug out and crash because of some snowballing glitch. For the most part, it seems benign. People are finishing games and such; I assume you're capable of having a pleasant, 100% completed game.
Experimenting on a separate save, I was able to get an accurate report of Sora's dive records, simply by not
rewatching any of the mementos. Of coarse, everyone wants to use that feature without ramifications, and no one wants to ignore it and see the "New" notice next to the option on the main menu at all times. This isn't anything wildly upsetting in itself, but it's a tad distracting for the ocd (such as myself), and it
should be corrected.
The main concern is when the special Link Portals get switched between Sora and Riku. From what I gather you need to complete all of these so you can obtain a keyblade, and you can't when the data confuses ones portals for the others. Dropping either manually or automatically, it's possible to adjust this error - that's how my characters got their respective portals back. I hope after this "fix" nothing will trip it up again. *prays*
Don't just "ignore it" though. Even if it is a minute issue, it's still an issue you shouldn't have to deal with. You should contact SE / Nintendo customer support.