PyQgis 3 Script for PDF Exporting not showing map?

Question

Im writing this script for exporting PDFs, I managed to get an output PDF as I wanted but its not showing the Map window. If i get into the Composer, the map is blank but magically refreshes and shows when I click on it.

Tryed refreshing the layout after I set extent and size of the map, but didn't work. Also tryed to open the layout through iface.openLayoutDesigner(layout) but that freezed QGis and forced me to terminate it. Here is the processig part of my script...

def processAlgorithm(self, parameters, context, feedback):
    input_featuresource = self.parameterAsSource(parameters,'INPUT',context)
    nomenclatura = '1.1.E.3.43' #str(input_featuresource)

    project = QgsProject.instance()
    QgsExpressionContextUtils.setProjectVariable(project,'Manzana_actual',nomenclatura)

    pScope = QgsExpressionContextUtils.projectScope(project)
    tx = pScope.variable('Manzana_actual')

    layer = project.instance().mapLayersByName('Mzs,Qt,Chs')[0]
    iface.setActiveLayer(layer)

    query = '"EJIDO" = ' + tx.split('.')[0] + ' AND "CIRC" = ' + tx.split('.')[1] + ' AND "RADIO" = \'' + tx.split('.')[2] + '\' AND "CC" = ' + tx.split('.')[3] + ' AND "MZNA" = \'' + tx.split('.')[4] + '\''
    layer.selectByExpression(query)  


    iface.actionZoomToSelected().trigger()

    projectLayoutManager = project.layoutManager()
    layout = projectLayoutManager.layoutByName("Manzanero")
    #iface.openLayoutDesigner(layout)

    vg = layout.itemById('ventanaGrafica')

    vg.setExtent(iface.mapCanvas().extent())
    vg.attemptResize(QgsLayoutSize(20.85,18.85,QgsUnitTypes.LayoutCentimeters))
    layout.refresh()

    base_path = os.path.join(QgsProject.instance().homePath())
    pdf_path = os.path.join(base_path, str(tx.replace('.', '_') + '.pdf'))

    exporter = QgsLayoutExporter(layout)
    exporter.exportToPdf(pdf_path, QgsLayoutExporter.PdfExportSettings())

    return {'OUTPUT': pdf_path}

I took out the comments cause they were not written in english.