How to pass radio button IsChecked property as command parameter

Right now I have a xaml page in MAUI .Net with the following radio button

<RadioButton x:Name="radioButton1"
                     Value="Player1"
                     Grid.Row="0"
                     Grid.ColumnSpan="2"
                     BorderWidth="1"
                     VerticalOptions="Center"
                     IsChecked= "True"
                     >
            
            <RadioButton.Content>
                <MultiBinding StringFormat="{}{0} {1}">
                    <Binding Path="Name1"/>
                    <Binding Path="Player1.Score"/>
                </MultiBinding>
            </RadioButton.Content>
            <RadioButton.Behaviors>
                <toolkit:EventToCommandBehavior
                        EventName="CheckedChanged"
                        Command="{Binding ChangeCurrentPlayerCommand}"
                        CommandParameter="{Binding Source={RelativeSource Self}, Path=IsChecked}"
                    />
            </RadioButton.Behaviors>
        </RadioButton>

And I the command is the following method on my ViewModel.

[RelayCommand]
        void ChangeCurrentPlayer()
        {

            if (CurrentPlayer == Player1)
            {
                CurrentPlayer = Player2;
            }
            else
            {
                CurrentPlayer = Player1;
            }

        }

I want to pass the IsChecked property of the button as a parameter to the command, but the application throws an exception of type:

System.InvalidOperationException: 'Operation is not valid due to the current state of the object.'

Is there any way I can do this?
The reason I need to pass that state as an argument is to get around the fact that whenever a radio button is clicked the command is fired twice in a row, making it useless, unless I have a way to know which button is currently calling it.

Behaviours don't have unique visual tree parents so we cannot use RelativeSource binding on it. Please refer to this issue: Relativesource bindings and behaviors.

As a workaround, you could try the following method.

in xaml, change the Binding for CommandParameter:

<StackLayout>
    <RadioButton x:Name="radioButton1"
         ...
         VerticalOptions="Center"
         IsChecked= "True"
         >
        ...
        <RadioButton.Behaviors>
            <toolkit:EventToCommandBehavior
            EventName="CheckedChanged"
            Command="{Binding ChangeCurrentPlayerCommand}"
            CommandParameter="{Binding Source={x:Reference radioButton1}, Path=IsChecked}"
        />
        </RadioButton.Behaviors>
    </RadioButton>

This binds the CommandParameter to the IsChecked Property of this radiobutton1.

And in viewModel, pass the correct parameter (IsChecked is bool type), like this:

[RelayCommand]
void ChangeCurrentPlayer(bool isChecked)
{
    var a = isChecked;   
    Console.WriteLine("123");
}

Hope it works.