I have two shipping methods withd ids ‘flat_rate:1’ and ‘free_shipping:2’ and two payment methods with ids ‘cod’ and ‘pumcp’.

Conditions:

1. When cod is selected I want to hide free_shipping:2 and show flat_rate:1.
2. When pumcp is selected I want to hide flat_rate:1 and show free_shipping:2
3. Both the payment methods should be visible and should not hide based on shipping method selection.

I am using following code from other stack overflow question but it hides cod payment method and I am unable to select that.

Can someone please explain what is the actual issue?

add_action( 'woocommerce_package_rates','show_hide_shipping_methods', 10, 2 );
function show_hide_shipping_methods( $rates, $package ) {   
    $chosen_payment_method = WC()->session->get('chosen_payment_method');

    if( $chosen_payment_method == 'cod' ){
        unset($rates['free_shipping:2']);
    } 
    else if ( $chosen_payment_method == 'pumcp' )
    {
        unset($rates['flat_rate:1']);
    }
    
    return $rates;
}

add_action( 'woocommerce_review_order_before_payment', 'payment_methods_trigger_update_checkout' );
function payment_methods_trigger_update_checkout(){
    ?>
    <script type="text/javascript">
        (function($){
            $( 'form.checkout' ).on( 'change blur', 'input[name^="payment_method"]', function() {
                setTimeout(function(){
                    $(document.body).trigger('update_checkout');
                }, 250 );
            });
        })(jQuery);
    </script>
    <?php
}

add_action( 'woocommerce_checkout_update_order_review', 'refresh_shipping_methods' );
function refresh_shipping_methods( $post_data ){
    $bool= true;

    if ( WC()->session->get('chosen_payment_method') === 'cod' ) {
        $bool = false;
    }
    
    if ( WC()->session->get('chosen_payment_method') === 'pumcp' ) {
        $bool = false;  
    }

    // Mandatory to make it work with shipping methods
    foreach ( WC()->cart->get_shipping_packages() as $package_key => $package ){
        WC()->session->set( 'shipping_for_package_' . $package_key, $bool );
    }
    
    WC()->cart->calculate_shipping();
}