Hi,

I found an error on the page. When I add two navigations with subnav, on mobile when I click ".sub-arrow" icon to open subnav it opens and hides. 

This is happening because the frontend script is triggered twice for each navigation and in the frontent.js script, there is a global event for "sub-arrow" class.

The solution for that is to limit appling "sub-arrow" event to single nav. Here is the part of the code should be changed (line: 6888):
Before:

subArrow: function subArrow() {
    var $ = jQuery;
    $(".sub-arrow").on("click", function (event) {
      event.preventDefault();
      $(this).parent().siblings("ul").slideToggle();
    });
  },

After:

  subArrow: function subArrow() {
    var $ = jQuery;
    this.$element.find(".sub-arrow").on("click", function (event) {
      event.preventDefault();
      $(this).parent().siblings("ul").slideToggle();
    });
  },

I already fix that error in your plugin folder so it works on my theme. I wanted just to let you know that there is that problem so you could fix that for future updates.

Basically, when you add two nav menus with at least 3 levels menu and you click the plus icon (on mobile) next to the element it opens and closes.