Failing characters with Merriweather font?

[AA_PDX]

With this page, em dashes (—) and apostrophes fail in the body text, leading to ugly, nonsensical substitute characters. Why? (Firefox 110, Mac.)  Screenshot attached.

[Anonymous]

Try validating your fonts: Install and validate fonts in Font Book on Mac.

If the issue persists, and only happens on Firefox, you can use this form to report it: https://webcompat.com/issues/new

[AA_PDX]

Thanks, but it's a web font, not on my local system, so I don't imagine FontBook has any effect on it...