Font not showing up in SAB

Hi everyone,
I’m trying to combine two existing apps: a storybook app and a NT app. They both use Charis SIL Compact and the font appears correctly in the two apps. However, in the combined app (I added the NT as a second collection in the storybook app, restricting the app to a single-pane view) the font that displays in both collections is a generic, sans-serif font. I’m not sure where that came from as the only font specified in the app (font1) is Charis SIL Compact, and font1 is selected everywhere I can see to specify a font, including all the styles. The font shows up as Charis SIL Compact correctly in the Viewer tab, and HTML output, but not in the app itself. Any ideas? Thanks!
Andrew