In WPF, this code:

<StackPanel>
    <RadioButton Content="Option1"
                 IsChecked="True"
                 GroupName="Options" 
                 HorizontalAlignment="Center"
                 Margin="0 40"/>
    <RadioButton Content="Option2"
                 IsChecked="True"
                 GroupName="Options" 
                 HorizontalAlignment="Center"/>
</StackPanel>

and with this code:

<StackPanel>
    <RadioButton Content="Option1"
                 GroupName="Options" 
                 IsChecked="True"
                 HorizontalAlignment="Center"
                 Margin="0 40"/>
    <RadioButton Content="Option2"
                 GroupName="Options"                     
                 IsChecked="True"
                 HorizontalAlignment="Center"/>
</StackPanel>

will get different result. And Why? I just adjust the order of GroupName and IsChecked.

I used the code in WPF with .net6 in VS 2022.
I expect to know why I get the different result.