Laravel 推送器滚动最新消息

聊天室不显示发送或接收的最新消息。当它到达某个点时，它只是停止滚动新消息

这部分是发送

function send(to_user, message){
let chat_box = $("#chat_box_" + to_user);
let chat_area = chat_box.find(".chat-area");

$.ajax({
    url: base_url + "/send",
    data: {to_user: to_user, message: message, _token: $("meta[name='csrf-token']").attr("content")},
    method: "POST",
    dataType: "json",
    beforeSend: function () {
        // console.log('adfasdf');
        if(chat_area.find(".loader").length  == 0) {
            chat_area.append(loaderHtml());

        }
    },
    success: function (response) {
    },
    complete: function () {
        chat_area.find(".loader").remove();
        chat_box.find(".btn-chat").prop("disabled", true);
        chat_box.find(".chat_input").val("");
        chat_area.animate({scrollTop: chat_area.offset().top + $(document).height()}, 800, 'swing');
    }
});}

这是用来接收的

function displayMessage(message){
// let alert_sound = document.getElementById("chat-alert-sound");

if($("#current_user").val() == message.from_user_id) {

    let messageLine = getMessageSenderHtml(message);

    $("#chat_box_" + message.to_user_id).find(".chat-area").append(messageLine);

} else if($("#current_user").val() == message.to_user_id) {

    // alert_sound.play();

    // for the receiver user check if the chat box is already opened otherwise open it
    cloneChatBox(message.from_user_id, message.fromUserName, function () {

        let chatBox = $("#chat_box_" + message.from_user_id);

        if(!chatBox.hasClass("chat-opened")) {

            chatBox.addClass("chat-opened").slideDown("fast");

            loadLatestMessages(chatBox, message.from_user_id);

            chatBox.find(".chat-area").animate({scrollTop: chatBox.find(".chat-area").offset().top + $(document).height()}, 800, 'swing');
        } else {

            let messageLine = getMessageReceiverHtml(message);

            // append the message for the receiver user
            $("#chat_box_" + message.from_user_id).find(".chat-area").append(messageLine);
        }
    });
}}

问题是当我发送或接收消息时，它不会显示最新消息。它会回到某一点上