Change event not firing on nested grids (resize, move...) #2671

var items = [{"x":0,"y":0,"w":6,"id":"5352223231011-3142222-410151-132321-200104202021152022100","subGridOpts":{"children":[]}},{"x":6,"y":0,"w":6,"id":"133014223145-112141-4112121-120214-43422114222221410","subGridOpts":{"children":[{"id":"01344140020-1013320-4151323-1521411-1140103111252101411","subGridOpts":{"children":[]},"x":0,"y":0},{"id":"412141422121-102202-42145-12152321-5223321101112214225","subGridOpts":{"children":[]},"x":3,"y":0}]}},{"x":0,"y":1,"w":12,"id":"1122021332120-2201014-4151315-1521145-12102130152142222321","subGridOpts":{"children":[]}}];

let options = { // main grid options
    resizable: {
        handles: 'se'
    },
    margin: 8,
    minRow: 2, // don't collapse when empty
    acceptWidgets: true,
    subGridDynamic: false,
    subGridOpts: subOptions // all sub grids will default to those
};


var grid = GridStack.init(options);
grid.load(items);

grid.on('change', function (event, el) {
      serializeFullGrid(grid);
  });