Screenplay Formatting confusion

Hello, first post.
I want to start a screenplay. When I copy the text from Scrivener sample script, the formatting doesn’t stay with it if I write. eg the margins for dialogue, which is quite narrow in centre of the page don’t hold if I start writing my own text. It just spreads out to the full page when it continues. There seems to be no format setting.

Are you sure Script Mode is active?

Thank you. I found it in FORMAT - SCRIPTWRITING - CHANGE ELEMENT TO…