Up- and down arrows and remove button do not work inside a document that has a two layer deep compound type

In our current setup we have the following document structure:

ChamberDocumentPage

• title
• last modified date

ChamberDocument (multiple, orderable)

• title
• file
• last modified date

Subfiles (multiple, orderable)

• title
• last modified
• file
• "verzamelstuk" checkbox

In this situation there is a nested multiple. The outter compound type (ChamberDocument) should show two arrows and a cross for deletion. As you can see in the screenshot, this is the case.

Subfiles are another multiple and orderable compound type. Unfortunately, when one adds a chamber document, and then presses the + on the subfiles type a few times, the expected interface elements (arrows and cross) are absent.

Furthermore, when one then proceeds to press the cross on the chamber document compound type, marked by (1) in the screenshot. The last subfile disappears, instead of the chamber document itself.

So, in short, the desired situation is:

• compound types of compound types should have arrows and crosses
• the remove button for a compound type should remove itself, not its last child.