I got it with current release to enter in two differnt backup jobs to set up the same target backup folder.
2nd job failed after 1st job already finished before.
Final result was, that directly after this attempt to re-use one single folder for my backuped files, that the Duplicati-db was corrupted. Didn’t got it fixed with the board tools.
Resolution was, to set up both jobs completely from scratch (it was necessary to delete them before!) and even the backup.
Wish: it should not be possible to reuse same folder in seting up a job via GUI, if it is known that this will corrupt a job’s backup. Or you enable this feature if it is one
So you can avoid disappointments for users rely on their backups