I’m using cardbook with Thunderbird and syncing to a Nextcloud (Owncloud) server. I have been experiencing problems with Vcard version 4.0, (specifically contact photos don’t sync) so I set preferred Vcard version to 3.0 in cardbook preferences. However when I create a new card in cardbook, it is still created as Version 4.0, and I lose data.
If I use Thunderbird Config Editor and manually change the string of extensions.cardbook.cardCreationVersion from 4.0 to 3.0 that works. So it seems that cardbook is not writing this value to Thunderbird config correctly?