Input of complex properties for custom schemas not created in custom document

Using Nuxeo FT 9.1, Web UI 1.0.0

• In Studio, create a custom document type including a schema with complex properties
• In View Designer, design the create layout with input fields for the complex properties
• In View Designer, design the view / metadata layouts to display each field of complex properties
• In Web UI, create a custom document, filling in all fields
  => The document is created without the complex property fields (values are all "null")

In this case, I refer to the juridicalContact property of the bccustomer schema, used by the BCPortfolio custom document type in the contract-management-nuxe (or karin-studio-tutorial) Studio project.

When I create the document in JSF, the complex properties are created and visible in the Web UI view layout.