fix(#5747): [react-aira: RadioGroup]: No tabindex/Can't keyboard focus to input until value is checked (#5755)
Looks like the default selected value in the example is an empty string, which is not the same as null. https://github.com/adobe/react-spectrum/pull/4985/files#diff-26ddea7c3bd0c2b48179af98635706a6391a01b59c936e8b497d1843a97ff202R71-R78
A more robust solution might be to validate whether the default value is one of the possible values within the radio group, but that's a bit more complicated.
Co-authored-by: Robert Snow <rsnow@adobe.com>
Co-authored-by: Daniel Lu <dl1644@gmail.com>