added to Views header (global unfiltered text) disappears with inspect element
Add your header (for quick testing purposes, so you don't need to add it to a css file)

&lt;style&gt;
 .some-class { border: solid red; }
&lt;/style&gt;


To double check that indeed it's not there.

If it's not there (you don't see anything red), then try using Global: Text area instead and use Full HTML as your text format.