Pocketbook Lux 4 Library Issue

[R777]

Hi, I have an issue with how the author's name is shown in Pocketbook's library>Authors - for epubs only the author's last name is shown (so, for example, "Austen" and not "Austen, Jane", whereas for pdfs, both FN and LN are shown, but for some reason, pdfs are sorted by FN (even though they appear as LN, FN in Pocketbook'a library>Authors).
My issue is mainly epubs, since I don't have many pdfs anyway.

I use Calibre to edit metadata, I do not copy files from Calibre Library, instead I export a book from Calibre in a folder to copy to the SD card. All the metadata except for LN, FN is successfully shown - I can see genres and book infos (not for pdfs, only for epubs - but like I said, I don't care about pdfs as much), which is why I don't understand why FN is the problem. I like using Author view more than Folder view, so I would really like to fix this.

Does anyone have an idea as to why this happens, why does Pockebook's library only show LN? Thanks!