@leocg Oh! what stupid! You are right! I have found it now in "Security and Privacy > Use a prediction service to help complete searches and URLs typed in the address bar."
Thanks for all!
@diezi hola no tengo activado sitio de escritorio. Probé a borrar los datos en configuración del sitio y sigue funcionando igual de mal. Pero desinstalé ópera y lo volví a instalar y se acabó el problema. Gracias por todo.
@burnout426 I reset Opera with opera://settings/reset , then reinstalled the extensions, adblocker, synchronization... and now I can see the video!!
The problem has been solved.
Thank you very much!