How to change the subheading language?

I have just found that the Title subheading in one forms has appeared as Italic but I cannot see where to change this. I have looked at the Advance Designer's CSS but cannot find anything that refers to Italic setting only Bold, Bolder etc. Where can I change this to Normal, don't even see it in Inspect either? 

Copied the CSS into Word and and searched for Italic, no sign of it at all should I be looking for the tag ? 

See image 

You can change the header in Header Text field is in Header Properties section.

Hope this helps!

No I am afraid that you have misunderstood the Query, it was how to change the Sub Heading text from italic to normal  or Visa Versa

Thank you for clarification.

You can set the sub-heading text by inserting the below CSS:

div#subHeader_3 {

    font-style: normal!important;

}

Just insert it in your Custom CSS field.

Let us know if you have any further questions.

Thank you!