Are you adding in codes like
<p>paragraph</p> to create paragraphs? If you are, there isn't a need to add any codes to create paragraphs. You should only need to use the 'enter' button on your keyboard to drop your text down to where you want the next paragraph to begin. Does that not work?
Look at your post from the html side and make sure you don't have some extra codes added into there. And, if you write your blog posts in a software program prior to pasting into your blog, don't ever use anything like MS Word because it adds in formatting that you may not see.
Looking at your post it appears you used the 'center' button for your content. Have you tried it without centering the text?
Not sure otherwise, why your wysiwyg editor or html editor wouldn't be doing paragraphs, unless your files in the backend are not right.