Block Title coding not showing Drupal 8

Question

My work's website currently uses Drupal 8 and to split up content we title sections and highlight it in green using this coding: <h2 class="block title"> Book Lists </h2> and then hit save, nothing happens. It works on all of our other pages except for one. It is literally the same coding on each page. I copied and pasted the HTML coding and still nothing shows.

Answer 1

I think there are two possibilities:

1. your CSS is being overridden or does not apply at all
2. the class attribute is being stripped out (eg if you're using CK Editor and the default "Simple HTML" text format)