Wrong created/modified dates

I have a project where a great many pages have the same (and wrong) created and modified dates in the inspector. In each case, the creation date is April 13, 2021 at 8:40 PM and the modified date is April 14, 2021 at 8:23 PM.

Even if I go to a backup of this project that hasn’t been opened since 2019, those pages have the same 2021 dates. Looking at the internal .scrivx xml file, the dates all seem to be proper 2019 and earlier. And within the Files/Data folder, macOS shows the correct dates.

Where could Scrivener be getting these dates?