Windows 10 Kaomoji panel categories have missing icons

I’m using Windows 10 20H2 en-US x64 (19042.572, fully updated). When I press Win+. or Win+; to bring up the Emoji/Kaomoji/Symbols panel, on the Kaomoji ‘tab’ the category icons at the bottom are missing and only boxes are displayed as you can see below:

Looks like a possible font issue, but how do I fix it?

(I tried a web search but the only mention on MS Community lacks a useful answer.)