Type (open type fonts) rendering with missing glyphs in PDF

I am running into an issue I've never had before in (newly downloaded) Indesign 2024.

I'm using open type fonts in this document, which show up perfectly fine on screen. But when I export as a PDF it renders as if half of the glyphs are missing. (screenshots below.) Note there are multiple typefaces in this document, all purchased through the same foundry at the same time (years ago), but this is the only one doing this.

I've looked through all of the PDF presets and done a bunch of tests and I can't figure out how to resolve the issue. Any ideas why this might be happening and how to fix?

Thanks!