I think that's the case, since the number of stories an actor/character/etc is cast in is supposed to only reflect public-facing ones, not private or unlisted. If there's more private/unlisted stories that they're cast in than there are public ones, the number drops into the negative because of... Some kind of coding issue that's a little beyond my expertise lol.

The same thing happened to me a few years ago. Nuked a fancast series for personal reasons, and I noticed that a lot of talents' numbers went in the negatives because they didn't have that many casting suggestions at the time, since it included a dub for a language that didn't have a whole lot of enthusiasts for its dubbing/VO scene on here.