If you are using PTXprint, and if those headings are using the \s marker, then you should be able to change the Style.
This will require you to be in the Full View so that you can see all the settings. Then go to the Styles tab and search for "s". Likely you'll need to change the Space Before Factor. Note that if that title is in Bold, just clicking the bold text may set the measurement back to the default and solve your problem.
