Inter's superscript font-feature-settings seems to be broken

I've tried copying the CSS code as used in Inter's [lab website](https://rsms.me/inter/lab/?feat-sups=1), where superscript works:

`font-feature-settings: "case" 0, "cpsp" 0, "dlig" 0, "frac" 0, "dnom" 0, "numr" 0, "salt" 0, "subs" 0, "sups", "tnum" 0, "zero" 0, "ss01" 0, "ss02" 0, "ss03" 0, "ss04" 0, "cv01" 0, "cv02" 0, "cv03" 0, "cv04" 0, "cv05" 0, "cv06" 0, "cv07" 0, "cv08" 0, "cv09" 0, "cv10" 0, "cv11" 0, "calt", "kern";
`

I haven't tested all of them, but many other font features work as expected, just not superscript.

I'm guessing this is something with Google Fonts since I've previously had this working with a self-hosted version of the font.