@hannes Full backup interval (and Force full backup in the schedule settings) forces the job to do a full export of the disk and not a delta based on a previous one.
It is not impacted by the retention as XO will always makes sure every chain has at least a full export at the beginning so that all backups are viable.
Which means you will have multiple full backups, always one at the beginning, and, those that have been triggered by the settings above.
