This is really a specific smashwords post. the aim in life with an ebook is to get it onto many lists as possible including fusspots apple. So do that, you have to pass through their autovetting process which is a complete style fascist. Well for good reasons, bad formatting does look dire.
The problem is you think your formatting is perfect, the machinery does not. So you are in a "you used a leading paragraph return together with an indented first line" purgatory.
Sigh, I always use a block paragraph at work but decided to conform with the indented first line paragraph style used for fiction.
Back to the drawing board!