Horn in F is creating a problem

I have designated my horn parts as “Horn in F” and am notating them as such, but they are sounding in C. How do I resolve this?

When viewing the relevant part/score, is Concert Pitch or Transposed Pitch selected in the Edit menu?

Thank you

That worked once I transposed the horn parts already written. Now how do I input the correct key signature? The work is in C, so the horn parts need to be in G.

If you have chosen Horn In F No key sig, the part will be transposed correctly but the sharps and flats normally found in its key signature will be written as accidentals. If the other version of the Horn in F has been chosen, the appropriate key signature (ie 1 flat less or 1 sharp more than the concert pitch key sig.) will appear when you set it for the whole ensemble. The notes will sound the same in both versions.

Edit:
I have attached a Dorico project which might help.

Horns in F.dorico (873.4 KB)

Thank you