Originally Posted by krzyk
Maybe try to install latest JB and one of the hack to confirm that JB is there, and then uninstall it and redo the factory reset.
That's exactly what I've been trying to do. But it always fails to install the jailbreak. I already tried 0.11.N (which, as far as I can tell, is the current jailbreak version) but haven't had any luck with it either.
The Kindle doesn't have a jailbreak installed at the moment. I'd argue to call it a vanilla Kindle despite its weird jailbroken-like behavior because I did uninstall the jailbreak, as I mentioned, a few months ago and by that definition it should be a vanilla Kindle once more.
I will try to do a few more factory resets, in hope it will fix whatever is making my head hurt.