[tomsem]

I had one squarish thumbnail, checked it in calibre and sure enough its thumbnail was square there as well. I updated the thumbnail and connected to send the fixed thumbnail.

But after calibre synced all of the side loaded books now have square cover thumbnails. It turns out that all of the cover thumbnails in the amazon-cover-bug folder are square! Calibre 'restored' these on reconnect, overwriting the rectangular ones.

So after removing the side loaded books, re-sending some new ones, and removing amazon-cover-bug folder, I once again have rectangular thumbnails.

I would need to rebuild the book with square thumbnail it seems, changing metadata had no effect.

It must still be the case Kovid does not have a Scribe to test on.