You may have something in the style just prior to your entries that is overriding your entry -- or you may have something in the style when you create the entry that is turning bold off.
You can place your cursor within the text before (and in the expanded text) and check out the style being applied by clicking the arrow to the right of Styles on the Ribbon. Locate the highlighted style in the list and hover your mouse over the drop down arrow to see specifics or click the down arrow to modify the style.