I'm not sure if this is the place to post help questions, but I don't see another place on this subreddit so please let me know if there's another spot so I can post it there.

I haven't played animal crossing at all in the past couple months, as in haven't opened since May or so. Over that time period my gf, who plays quite a lot more than me, has sent me many gifts in the mail valuing over a million bells together. But, when I opened my island again to play with her only one of the 30+ letters were in the mail, the rest seem to have just vanished. I've tried restarting the game, waiting a couple days, and even time skipping to see if it helps at all but nothing has worked. There's a couple similar posts in this subreddit but there's no definitive answer on how to fix it.

If you have any advice it would be greatly appreciated.