No, that's not exactly what I'm doing. I'm doing nothing at the device, I expected the plugin to do it

And I'm not using the update metadata function either.
That's the problem, I think, I was only using "update status", expecting it to mark books as unread. "Wading into Murder" is not a problem, as it is my current reading. I'll clear the status through the other function and that's all.
Thank you very much.