Setup "Framework CSS Style Lookup Page" for custom CSS doesn't work

1. Follow Oracle® Application Framework Personalization Guide Release 12.2 on page 61
2. Use the function FWK_CSS_LOOKUP (Framework CSS Style Lookup Page) to test the style type defined in the $OA_HTML/cabo/styles/custom.xss

<!-- Please start your customizations here -->
<style selector=".XXCustomStyle">
   <property name="font-size">16pt</property>
   <property name="color">#ff0000</property>
   <property name="background-color">#ff0000</property>
</style>


<!-- Please end your customizations here -->
3. Item Style chooes "Static Styled Text", Style Type choose "XXCustomStyle", but the results styles applied is not what we define