jquery-ui sortable - moving tasks between lists

I'm trying use jquery-ui sortable connected lists and persist sorting changes in a Rails app.

1. Lists have many tasks.
2. Lists can be sorted among each other - works.
3. Tasks can be sorted among each other - works.
4. Tasks can moved between lists - does not work correctly:

Lists/index.html.erb:

<div class="list-sortable connectedSortable" style="cursor: grab;">
  <% @lists.each do |list| %>
    <%= content_tag "div", id: "list-#{list.id}", data: { model_name: list.class.name.underscore, update_url: list_sort_path(list)} do %>
      <%= render 'lists/list_preview', list: list %>
      <div class="task-sortable connectedSortable" style="cursor: grab;">
        <% list.tasks.rank(:row_order).each do |task| %>
          <%= content_tag "div", id: "task-#{task.id}", data: { model_name: task.class.name.underscore, update_url: list_task_sort_path(list, task)} do %>
            <%= render 'tasks/task_preview', task: task %>
          <% end %>
        <% end %>
      </div>
    <% end %>
  <% end %>
</div>

application.js:

require("jquery-ui-dist/jquery-ui");

$(document).on('turbolinks:load', function(){
  $('.list-sortable').sortable({
    cursor: "grabbing",
    //cursorAt: { left: 10 },
    placeholder: "ui-state-highlight",
    update: function(e, ui){
      let item = ui.item;
      let item_data = item.data();
      let params = {_method: 'put'};
      params[item_data.modelName] = { row_order_position: item.index() }
      $.ajax({
        type: 'POST',
        url: item_data.updateUrl,
        dataType: 'json',
        data: params
      });
    },
    stop: function(e, ui){
      console.log("stop called when finishing sort");
    }
  });

  $('.task-sortable').sortable({
    cursor: "grabbing",
    //cursorAt: { left: 10 },
    placeholder: "ui-state-highlight",
    update: function(e, ui){
      let item = ui.item;
      let item_data = item.data();
      let params = {_method: 'put'};
      params[item_data.modelName] = { row_order_position: item.index(), list_id: item.index() };
      $.ajax({
        type: 'POST',
        url: item_data.updateUrl,
        dataType: 'json',
        data: params
      });
    },
    stop: function(e, ui){
      console.log("stop called when finishing sort");
    }
  });

  $( function() {
    $( ".list-sortable, .task-sortable" ).sortable({
      connectWith: ".connectedSortable"
    }).disableSelection();
  } );

});

As I understand, the problem is in this line:

      params[item_data.modelName] = { row_order_position: item.index(), list_id: ??????????? };

I can not figure out how to pass list_id correctly (as the list.id to which the task was dragged)

Github repo: https://github.com/yshmarov/jquery-sortable-rails

Heroku demo: https://jquery-sortable-rails.herokuapp.com

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