Folder strucutre and tags are lost after synchronization

After export from OneNote via Evernote through enex files. All tags and folder structure of the notes is totally ok. However after synchronization (Owncloud webdav, dropbox) all imported notes loose their tags and go to the “All notes” section without any folder structure.
Is it my mistake, or there is really no way to synchronize folders and tags?
Thanks in advance.