when generating metaddata fields with no qualifiers in the Angular UI, there is following effect
- first SUBMIT in UI with missing qualifiers. coding = null
- next SUBMIT in UI with missing qualifiers. coding = ""
- first SUBMIT in UI and click in the qualifiers field, coding = ""
when there is an empty string in the qualifier field, these field are displayed and you can edit the values in the UI, however the storage in the backend does not work.