LO Direct formatting in Writer affects other paragraphs

Using Libre Office on Mac under Mountain Lion.
In Writer, when I apply direct formatting to a paragraph previously custom-formatted by paragraph style, the changes affect not only the paragraph I meant to change but all paragraphs above with same custom-format.
Hitting ‘delete’ does not reverse this.
This behavior is unwelcome. Is it deliberate? Can I keep LO from doing this?


blush Yes, it was AutoUpdate. Thanks.

Maybe the style has the AutoUpdate marked.