Added synchronous DOM mutation listener to a 'DOMNodeInserted' event. JavaScript

Скоро крыша поедет от JS

Ошибка в devtools: [Violation] Added synchronous DOM mutation listener to a 'DOMNodeInserted' event. Consider using MutationObserver to make the page more responsive

html

<script>
    $(document).ready(function () {
        // catch the form's submit event
        $('#ajax-service').keyup(function () {
            // create an AJAX call
            $.ajax({
                data: $(this).serialize(), // get the form data
                url: "{% url 'ajax_request' %}",
                // on success
                success: function (response) {
                    console.log(response);
                    if (response.is_exist) {
                        console.log("TYT");
                        let list = ''
                        for (var i in response.is_taken) {
                            list = list + '<span name="'+(response.is_taken[i])+'" id="'+(i)+'">'+(response.is_taken[i])+'</span> '
                            }
                        //console.log("i: "+i);
                        //let elem_input = document.querySelector("ajax-service")
                        //let elem = document.querySelector("#service"+i);
                        //console.log("response: "+response.is_taken[i]);
                        //console.log("elem: "+elem);
                        $('#ajax-service-list').remove();
                        $('#ajax-service').after('<div id="ajax-service-list" name="ajax-service-list">'+(list)+'</div>')
                    }
                    else {
                        $('#ajax-service-list').remove();
                        $('#ajax-service').after('<div id="ajax-service-list" name="ajax-service-list"><span class="badge rounded-pill bg-warning text-dark" id="ajax-service-list">Нет совпадений</span></div>')

                    }
                },
                // on error
                error: function (response) {
                    // alert the error if any error occured
                    console.log(response.responseJSON.errors)
                }
            });
            return false;
        });
    })
</script>

в чем дело? только что работало и вот