I have a recurring problem in 2.8.6 when I place text in H3 format between 2 r/l justified paragraphs. What happens is that the blank carriage space which appears in the text editor after the H3 tag, does not appear when the post is published.
I have noticed that if I move the opening <p> tag which introduces the justified paragraph of text after the H3 to be immediately before the H3 opening tag, this problem does not occur. But this violates HTML tradition.
However this solution does not work when the H3 tagged text begins the post. In that situation the paragraph which follows, adheres immediately to the h3 tag beneath it, without any intervening blank space/carriage return.
This error is maddening. But does not occur if the paragraphs before and after the H3 tagged text are not justified one way or the other in the visual editor, for then when published they appear left justified with a white or blank carriage return before and after the H3 tagged text.