2.1.257 Part 1 Section 17.7.8, Paragraph Styles

a.   The standard specifies that the resolved value of the toggle properties will toggle the previous level (True) or leave it unchanged (False) when present in a paragraph style.

Word resets the value of the toggle property to the value specified by the paragraph style if a value is present; for example, a value of 1 resets the property's state to True instead of toggling it.