Backup was uploaded to server repository, but it is not listed in. When trying to check backup:
# /usr/local/psa/bin/pleskrestore --check-backup /var/lib/psa/dumps/domains/example.com/backup.xml The specified backup file is corrupted, modified, or created on another server. To restore it, use the -ignore-sign option.
Since Plesk 11.0, Plesk encrypts backups with a server-specific, randomly generated key.
If backup was uploaded to another server this key will be different and this backup will not be listed in server repository list.
To restore such backup refer article: #116792