We add custom HTML/CSS to some articles as a way to draw the attention of our customers. When I used the new editor, whether it's on a new article or migrating an existing article to the new editor, the custom HTML/CSS appears to merge itself into the next class.
Using the legacy editor and works as expected:

Using the new editor and does not work as expected:

This causes the text not to appear as we want it to when previewing or publishing the article.
Due to this, we have to switch back to the legacy editor, update our changes again to ensure that it appears properly and then publish the article.
