Abbrev Title Displays in Courier Font

I use the <$abbr_title> field to keep track of the current version of my book. I put that on the title page, which is in different places for the eBook and Print Book versions.

However, I’ve found that it displays in Courier font. This illustration shows how it looks in the Scriv file (above) and in the PDF (below, in red box):

Is there a way to fix that?