Problems with changing clefs using Sibelius First music editing software

Are there any Sibelius First users out there? Here I mean the music editing software.

I’m working on an arrangement for woodwind quintet and I am having a very strange problem. I need the horn part to have changing clefs through the piece for practical reading reasons. I change the clef in the score and everything is fine. But when I go to print the parts, the clef is unchanging, despite changes I made in the score. This is maddening.

In older versons of Sibelius there was an “extract parts” function which did just that, and it gave you parts you could further edit. Not so the case anymore it seems. Just an unalterable print version, which means you have to be DAMN meticulous with the score. Am I overlooking something? There seems to be only a print function with no ability to edit.

I used earlier versions of Sibelius and always found it useful. This new is wonderful but I never had had this clef issue before.

I REALLY need this to work and if I need to resort to writing it out by hand I need to get started on that. I would rather resolve this though. Any help? Please?
Thank you in advance,