I need to set up a custom add to cart button with the product ID added.
This is the code I have and it works perfectly.

function custom_add_to_cart_button_with_quantity_shortcode($atts) {
   
    $product_id = isset($atts['product_id']) ? intval($atts['product_id']) : null;

    if ($product_id) {
        ob_start();
        ?>
        <form action="<?php echo esc_url(wc_get_cart_url()); ?>" method="post" class="cart">
            <div class="quantity">
                <input type="button" value="-" class="minus">
                <input type="number" step="1" min="1" max="" name="quantity" value="1" title="Qty" class="input-text qty text" size="4" pattern="[0-9]*" inputmode="numeric">
                <input type="button" value="+" class="plus">
            </div>
            <button type="submit" class="single_add_to_cart_button button alt">Buy Now</button>
            <input type="hidden" name="add-to-cart" value="<?php echo esc_attr($product_id); ?>">
        </form>
        <script>
            jQuery(document).ready(function($) {
                $(".plus").click(function() {
                    var currentVal = parseInt($('input[name="quantity"]').val());
                    if (!isNaN(currentVal)) {
                        $('input[name="quantity"]').val(currentVal + 1);
                    }
                });
                $(".minus").click(function() {
                    var currentVal = parseInt($('input[name="quantity"]').val());
                    if (!isNaN(currentVal) && currentVal > 1) {
                        $('input[name="quantity"]').val(currentVal - 1);
                    }
                });
            });
        </script>
        <?php
        return ob_get_clean();
    } else {
        return 'ID del prodotto non valido.';
    }
}
add_shortcode('custom_add_to_cart_button', 'custom_add_to_cart_button_with_quantity_shortcode');

The problem comes when I add two buttons, for two products, on the same page.
The quantity increment goes by two (1 – 3 – 5)
How can I solve this problem?`