Radio Button defaultChecked property not working

Hi all,

I have a problem using a radio button with the “defaultChecked” property - somehow it does not work for me.

The code in question is inside a CustomFieldEdit.
The snippet in question:

<Fragment>
    <RadioGroup name="saveEditedValues" isRequired>
        <Radio defaultChecked label={restoreText} value="false"/>
        <Radio label={overwriteText} value="true"/>
    </RadioGroup>
    <FormCondition when="saveEditedValues" is="true">
        <Select label={riskText} name="risk" >
            {RISK_VALUES.map((risk) => (
                risk == oldRiskValues.risk
                ? <Option value={risk} label={risk} defaultSelected />
                : <Option value={risk} label={risk} />
            )) }
        </Select>
        <Select label={complexityText} name="complexity">
            {COMPLEXITY_VALUES.map((complexity) => (
                complexity == oldRiskValues.complexity
                ? <Option value={complexity} label={complexity} defaultSelected />
                : <Option value={complexity} label={complexity} />
            )) }
        </Select>
        <TextField label={`${testIntensityText} (1-100)`} name="testIntensity" type="number" defaultValue={oldRiskValues.testIntensity}/>
    </FormCondition>
</Fragment>

Here a screenshot of the opened edit window:

Is this a bug?