Vivlio Light (PocketBook Verse) - Incorrect genre on device

[somewhatavidread]

Another puzzling quirk of my new Vivlio Light.

The issue seems to be related to this one, but not exactly the same.

What I did:

1. Formatted the internal storage and SD card
2. Factory reset the device
3. Set up the device but made sure to NOT enable Wi-Fi
4. Sent 159 books to the device from Calibre

The outcome:

Almost all tags from Calibre correctly translated to genres on the device, except for two: the tag "Science" in Calibre showed up as "Autre littérature scientifique (non incluse dans d'autres catégories" in the device's library, and "Poetry" showed up as "Poésie".

The <dc:subject> tags of both books are exactly the same in Calibre and on the device. I don't understand where the device's library pulls those other genres from.

I am attaching two screenshots:
- The first one shows one of the book's content.opf in Calibre
- The second one shows what the same book's content.opf looks like once it's added to the device (viewed using Sigil)