hey you can click h1, h2 etc
when you had a textformat applied already, it will stay the same, even if its now an h1 tag
for example, first you have a paragraph:
<p>sadadsas</p>
then you select a textformat from the dropdown, now the html is this:
<p class="_Shop_Big">sadadsas</p>
now you click the h1 tag, and the markup looks like this:
<h1 class="_Shop_Big">sadadsas</h1>
the markup changed, but the style of the text remained the same
click the <> code icon in the texteditor to see if you had a h1 applied
if you want both a style and the type of headline, use a textformat that has the headline type