Seems you actually have the Times New Roman font file on your system. Did you install one of the AUR ttf-ms-fonts packages at some point? If so, the ttf-ms-fonts package is notorious for being incomplete and for missing modern hinting info. There are newer ttf-ms font packages in the AUR, but require access to Windows installation media to build. There are also a couple that will automatically retrieve the 90-day evaluation edition of Windows to extract the fonts from, but seems very out of the way to me. I've just learned to live without MS fonts on Linux, myself. But the ArchWiki has a useful page on them:
https://wiki.archlinux.org/title/Microsoft_fonts
I'm still not certain how you've determined Bibi is using Times New Roman, though. Is that being forced in the EPUB itself somehow?