[Lusephur]

Originally Posted by NiLuJe

This has been reported to trigger in some exceedingly rare cases with some specific old (or not) kernels on some specific devices (so far, all of them Mk. 6).

I'd never heard of it happening in Nickel, though.

On a KA1, where the behavior is exactly what you describe: https://github.com/koreader/koreader/issues/5571

On a Glo HD, where it's a tad different: https://github.com/koreader/koreader/issues/5916

TL;DR: Does it happen with *every* book, or with a specific one only?

The KA1 link you posted seems to refer to exactly what I'm seeing.
Does it happen on every book? No, but then again, I can't be certain. Current book it's happening with is The Locked Room by Maj Sjowell and Per Wahloo, previous book, The Misty Harbour by Georges Simenon didn't, but that's a quickish read, book before that, Dog Soldiers by Robert Stone did, as did The Abominable Man by Sjowell and Wahloo, but not The Madman of Bergerac by Simenon and certainly with Tapping the Source by Kenn Nun. (Sorry, for the list and specificity. But, all are retail bought via amazon and converted to epub on calibre and then kepub upon transfer.)
So, in relation to your question, Maigret scares the bejaysus out of the issue.
It seems it could be after a certain length of time something happens.
I could reflash with the latest update and see what that does. But I wouldn't know if that solves it or not for days.