Python: broken wxVTKRenderWindow and wxVTKRenderWindowInteractor

Problem

I'm trying to run the wxVTKRenderWindowConeExample function from the file vtkmodules.wx.wxVTKRenderWindow on ubuntu 20.04 and on windows 10.

The example is not working and it's just showing an empty window (black on linux, white on windows).

The same problem occurs with the example in wxVTKRenderWindowInteractor

Observations

Both wxWidgets and VTK alone are working properly. I run examples from both the software and they are working properly. I also tried to took the code inside the function wxVTKRenderWindowConeExample and commented everything a part from the definition of the window and of the class wxVTKRendererWindow:

import wx
"""Like it says, just a simple example.
"""
from vtkmodules.wx.wxVTKRenderWindow import wxVTKRenderWindow
from vtkmodules.vtkFiltersSources import vtkConeSource
from vtkmodules.vtkRenderingCore import vtkActor, vtkPolyDataMapper, vtkRenderer

# every wx app needs an app
app = wx.App(False)

# create the widget
frame = wx.Frame(None, -1, "wxVTKRenderWindow", size=(400, 400))
widget = wxVTKRenderWindow(frame, -1)

#ren = vtkRenderer()
#widget.GetRenderWindow().AddRenderer(ren)

#cone = vtkConeSource()
#cone.SetResolution(8)

#coneMapper = vtkPolyDataMapper()
#coneMapper.SetInputConnection(cone.GetOutputPort())

#coneActor = vtkActor()
#coneActor.SetMapper(coneMapper)

#ren.AddActor(coneActor)

frame.Show()

app.MainLoop()

Since the result is equal with the commented code and without the commented code I think that the problem is that the renderer is not rendering the actor.