Bug with Uncial charactersd on French UI

The english part is OK but switching to french removes the Uncial characters:

N#575930

I see the same behavior on Firefox and Chrome.

Looking in the developer tools the two pages have the same list of fonts for that text, but a different font is selected.

font-family: "NumismaticaMedievalisModified5", "Source Sans 3", sans-serif, "Mongolian Baiti", serif;

Looking at the console I see many cross-origin error messages from the French page. It appears fr.numista.com is trying to load resources from en.numista.com. This doesn't seem to be specific to my configuration as I see the same result in a new Firefox profile.