I have used the Multigroup plugin and I have around 500 records that are updated every 10 seconds through a websocket:

updateDevices: function (array) {
    var i, store, entity;
    store = Ext.getStore('Devices');
    for (i = 0; i < array.length; i++) {
        entity = store.getById(array[i].id);
        if (entity) {
            entity.set({
                status: array[i].status,
                lastUpdate: array[i].lastUpdate
            }, {
                dirty: false
            });
        }  
    }
}

The panel renders fine, but when I try to click on the groups the click event does not work, I have to click more than 3 times to scroll the data, likewise to select a cell I have to click several times to make it appear select.

MultiGroups MultiGroups Click

How can I solve this problem?