@gelbschlumpf Yep, that's it. I jailbreaked? jailbroke? ... tried to disenshittify mine – let's call it civil disobedience. But it still connects to the Amazon server. I put KOReader on it and yes, I can read epub files now (which I store in a hidden folder, so Amazon should not be able to index them). It's a nice device and I'll keep it for the hopefully ever fewer authors whose books I need and can't get any other way but it'll land in the drawer as soon as I have a Pocketbook again.