Thank you for the reply. I'm sorry that I haven't taken your advice, but I'd already spent 17 hours on the character and, even though that's relatively little time in the long run, I'd rather not lose the time if possible.
I did a bit of research, and it looks like my character (Metafox) is being mixed up with someone's old character (Maruutaruu). If you search for these character names on the website's auction house page, they both return the same sale records. My character also seems to share this other character's bazaar history as well. The other character's auction house history ends around 5 months ago, so it looks like that character was either deleted or went inactive.
Looking through more recent threads, it looks like this person had a similar issue:https://na.nasomi.com/forum/viewtopic.php?f=7&t=11145
and it looks like this person had the exact same issue:https://na.nasomi.com/forum/viewtopic.php?f=7&t=9935
I'd like to try to contact nasomi and see if this could be a quick fix, but NasChat says that I'm only supposed to send a PM if it's about an exploit or security-type issue. Is that there just to scare people away from spamming him, or will I get in trouble for sending a PM about this?