Macro with a mandatory parameter of type enum with a default value cannot be inserted

When defining a macro with a parameters with the following properties:

• mandatory: Yes
• parameter default value non null (for instance SAFE)
• parameter type = fqn of an Java enum (for instance org.xwiki.annotation.maintainer.AnnotationState)

Trying  to insert a macro with such parameter using the rich editor do not allow the insertion of the macro when the default value of the field is selected (it's working with the other values of the enum).

Inserting the macro manually displays it properly.

To reproduce, see the attached xar.