Line Height

The line height in the app Iꞌm building is a little bit tight to my taste. Is there any way to change the overall line height, without having to adjust each individual paragraph style?
In the book collection, Styles tab, there is a setting “Default Line Height”. However, no matter what I enter here, this does not affect the line height in the text - it seems to be overridden by another setting. But where? The line height setting in styles like “body” and “div.p” is empty, so I would expect it to use the default line height.