Subsequent button actions not possible on single tap

Button actions are not being fired on single tap on a multi-panel screen. But on double tap the same is being fired.

The screen has multiple panels. Attaching the code below :

Code:

Ext.define('SenchaApp.view.Main', {    extend:'Ext.Container',
    xtype: 'main',
    requires: ['SenchaApp.view.panel1','SenchaApp.view.panel2'],
    config: {items: [{xtype : 'panel1'},
                                {xtype : 'panel2'},]}
});

Code:

Ext.define('SenchaApp.view.panel1',{
    extend: 'Ext.form.Panel',
    xtype: 'panel1',
    config: {
        title: 'panel1',
        docked : 'left',
                style : 'width: 5em; height: 5em;',
                layout : 'vbox',
        items: [{
                                        xtype: 'button',
                                        text: 'Display',
                                        listeners: {
                                        tap : function(){
                                                alert('Display tapped');
                                                Ext.ComponentQuery.query('#board')[0].setValue("Displayed");
                                }}},{   xtype: 'button',
                                                text: 'Alert',
                                                listeners: {
                                                tap : function(){
                                                        alert('Alert');
                                                }}
                                }]}
});

Code:

Ext.define('SenchaApp.view.panel2',{
        extend:'Ext.Container',
        alias:'panel2',
        xtype: 'panel2',
        requires : ['SenchaApp.view.panel3'],
        config:{        
                style : 'height: 100%;',
                layout:{
                        type:'card'
                },
                items : [{
                        xtype : 'panel3',
                }]
        }
});

Code:

Ext.define('SenchaApp.view.panel3',{
        extend:'Ext.Panel',
        alias:'panel3',
        xtype: 'panel3',
        requires : ['SenchaApp.view.custompanel'],
        config:{
                style : 'height: 100%;',
                items : [{      xtype : 'textfield',
                                        label : 'BOARD',
                                        itemId : 'board'
                                },{
                                        xtype : 'button',
                                        text : 'SUBMIT',
                                        itemId :'submit',
                                        listeners: {
                                        tap : function(){
                                                alert('Submit');
                                        }}
                                }]
        }
});

Behavior : On clicking the 'Display' button, Display message is shown in the textbox. On single tapping the alert, no alert box is show. The same behavior is shown for 'submit' button.

Expected : On single tap of 'Alert' button, an alert should be shown.

Anyone faced any similar scenarios ? Please advise.

Subsequent button actions not possible on single tap