Possible bug: Incorrect ISBNs prevent metadata download.
Steps to replicate.
1. Set metadata providers to only Kobo Metadata.
2. Set country to Canada. (May not be necessary.)
3. Add this book:
Title: Halo: Contact Harvest
Author: Joseph Staten
ID:
kobo:halo-contact-harvest-8
4. Attempt to download metadata. It should fetch it.
5. Now add
isbn:9784878920110 to the IDs field. (Note: This is actually an ISBN for a completely different book;
a character has a military service number '48789-20114' which coincidentally is a valid ISBN-10. ISBN Extract picked it up and my metadata processing converted it to the 13 form.)
6. Now the metadata fails to download.
The Kobo Books plugin downloads the metadata with an incorrect ISBN.