Problem with huge font in Mobi file on kindle

I recently upgraded to the new version of Scrivener (Windows) and when I try to compile a Mobi file now, the font shows up HUGE on my kindle–as in, only 20-30 words per page. So big I can’t decrease it enough in my kindle settings to be readable. I’ve tried to search to see how I fix this–my fonts are set to 12pt in the editor. How do I fix this Mobi compile problem? I never had an issue with the previous version. Thank you!