OS 10.13.6
Scrivener latest version
The Style Panel on High Sierra is not usable. Is it possible to fix that?
macosxguru
Is this still an issue in the latest version, 3.1.5? For problems like this I would always try a quick reinstall anyway, but you might as well upgrade if you haven’t, and kill two birds with one stone.
One other thing to check, as I believe some of the base formatting attributes for presenting this list are established from default settings, is to make sure you don’t have any unorthodox line height settings there. In particular, I suppose one might see something like this if they force the line height to 12pt but then set the base font size to 18pt.