Cor en Fa à la place de Cor anglais

when I create an English horn part, the name Horn in F is written on the score. However, the sound is that of the English horn. I have to change it manually but I can’t manage to change this behaviour permanently.

It sounds as if you may have at some point overridden the default name of the English horn instrument and then saved that change to your user library. Start a new project, and go to Library > Instruments and look for English horn in the list. Check to see whether the little star icon in the action bar is filled. If it is, click it so that it becomes unfilled. That will resolve the problem for future projects.

In your current project, open the Edit Instrument Names dialog, and click Reset to Factory.

Thanks Daniel
everything is back to normal.