Cruft in JSON List export?

Hi there, I noticed an odd behavior in my JSON export. I have named lists (strings) that sometime include the same items. Occasionally, I move items around or delete lists. On export, these latter cases seem to cause problems. For example, where I’d expect my @list output to look like this:

['matches', 'matches 5', 'matches 14']

it instead looks like

['matches', 'matches 5', 12] where the last item is an integer rather than a string. It seems like maybe the JSON export is retaining vestiges of a deleted list? Do others get this cruft in their exports?