smooth scrolling welcome button not working with sec language – qtranslate

Hello
First of all you can see my test site in: https://gbadvisors.staging.wpengine.com/

The problem Im facing is the smooth scrolling to #site-navigation anchor works fine in English language (set as my first language) But, when you turn to spanish the welcome button seems to reload the page instead of making the scrolling with the smooth effect, which I prefer.

Is there a way to prevent this behavior ???
Im using qtranslate plugin for language switching

Thanks in advanced