I think that I got the same problem with Calibre-converted ePubs.
After conversion there ist nor cover art anymore
Tried different setting in Calibre
- no SVG Cover (Output-Options)
- use Cover art from Source-File (seperate Book-conversion)
- no predefined Cover (Output-Options)
Dont know if these setting are named so in english because in german
they would read as:
- Kein SVG Umschlagbild
- Umschlagbild der Quelldatei verwenden
- Kein voreingestelltes Cover
In the page-setting I did use as "reader"
"Generic e-ink large"
But nothing brings back the Cover (art) :-(