Reveal.js Markdown fragment with inside formatted element fails

i try to apply fragment class to list element in Reveal.js via Markdown :

If the list element contain only text it's works, but if the list element contain a formatted inside element, fragment class is applied to that inside element. next next

Is there a way to avoid this?

Thanks

P.S. : the problem is not limited to list element : it's the same with simple text lines