Button display function messing up with custom CSS

Hi there,

I’m using the button display shortcode [printfriendly current=’yes’] because I want it to be displayed only on a specific page. I removed the option of showing the button on all the pages and posts from the settings. Now, if I download/print the pdf of the page, the custom CSS works only partially, but if I show the button on all the pages, the custom CSS works fine. Can you help me with this?

Thank you!