3D FlipBook - On the mobile version, after enlarging the PDF, it is not legible

Hi

I work now on a new website, and I used Your plugin

My problem is: on mobile phones some of the PDF's, if I make it biger, looks perfect - for example on: https://www.restauracjabartosz.com.pl/menu-dzienne/

but the MENU on mobile phones, if I make it bigger, looks blurred on: https://www.restauracjabartosz.com.pl/okolicznosciowe/ https://www.restauracjabartosz.com.pl/dodatkowe_informacje/

What its the reason for it ?

Kr RObert