I found follow issue:
I've created zPool with two drives, then a "Filesystem" with my files and folders. One folder has a mount point /zpool/smb/<Dokumente> and it's shared, after that I created "Sub-Filesystem" named "docker". Now my shared folders have this mount point "/zpool/smb/docker/..." which is wrong. To reproduce I've set the moint point to /zpool/smb/ again and created a further "sub-filesystem" named "test99". Result you can see on pictures.