Can't see Datas in grid second tabpanel despite store loaded

I've a tabpanel with 2 panels.

In the second panel when I load the store the datas are not showed in grid.

It works fine until I have added a second login view before loading my app view.

Code:

        
region: 'center',
        xtype: 'tabpanel',
        listeners: {
            'tabchange': function(tabPanel, tab){

                if (tab.id == 'ongregion') { // pour renseigner les compteurs des grid
                    if (!storeregion.isLoaded()) {
                        storeregion.load();
                        Ext.get('nbregion').setText('Nombre de regions : ' + storeregion.getTotalCount());
                        Ext.get('nbstockreg').setText('Nombre d\'éléments : ' + storestockregion.getTotalCount());
                    }
                }
            }
        },

The method to show app view after login :

Code:

                       success: function(result, action) {
                                WinLogin.hide();
                                Ext.get('loading').show();
                                var mainappli = Ext.create('StockApproApp.view.main.Main');
                                Ext.widget('app-main');
                                Ext.get('loading').hide();
                        }

Can't see Datas in grid second tabpanel despite store loaded