Resolve #3455370 "Append additional default"

Closes #3455370

src/SchemaDotOrgMappingManager.php

@@ -398,6 +398,9 @@ class SchemaDotOrgMappingManager implements SchemaDotOrgMappingManagerInterface
         continue;
       }
 
+      // Append additional default field properties.
+      $field += $this->schemaEntityFieldManager->getPropertyDefaultField($schema_type, $property_name);
+
       // Add Schema.org type and property to property values.
       $field['schema_type'] = $schema_type;
       $field['schema_property'] = $property_name;