Radio buttons not recognised in Safari (iOS 15.6.1 && 15.7.7)

Safari in Apple’s iOS 15.6.1 / 15.7.7 doesn’t render the radio buttons that I use, but will others.

It’s not an issue in iOS 16.7.8, sure, but is there anything I can do to fix this issue ?

It is also not an issue in Firefox (v115.4.0es) or Safari (v13.1.1) on a desktop (macOS).

The page : http://corkeprojects.co.uk/

I don’t have those old versions to test so don’t know if there’s an easier answer but generally I would use a label and style that instead of the radio and just visually hide the radio buttons.