Formatting of Parts Disappear when exporting to PDF, why?

Hello, I keep spending quite a while formatting individual parts from the main score to ensure they fit onto 2 pages (Stretch -Decrease) and staff heights etc therefore, not just having 3 bars on the next page. Ive just done this for an entire orchestra and also just a quintet piece to see if it happens anywhere else, and it does change.

After formatting the score and each individual part I export to pdf and all of the formatting has gone! It is still all formatted correctly in Musescore but the output is like it was before I made any changes.

I am 99% sure this didnt used to happen and as far as I can remember I dont think Ive changed any setting?
Ive attached the quintet file if that helps?

Can anyone help? Thanks in advance