This tutorial will show you how to rebuild the icon cache to clear and reset it for your account in Windows 10 and Windows 11. The icons that display for files in Windows are saved in an icon cache so they can be displayed quickly instead of having to manually scan and slowly load them each...
Could be a problem with either the "Segoe MDL2 Assets" font or the "Segoe Fluent" font.
Check the fonts are present in Settings > Personalisation > Fonts, then under Available fonts, type 'Segoe' into the search box, and see if both fonts appear in the search results.
Do the buttons still work when you click on them, is it just a font issue?