I see. Let me test version 11.28.1 first. How do I update my current pdf24 installation to the version 11.28.1?

Please watch the screen recording: https://www.screenpresso.com/=E77a2IBKhX8T Notice that at each scroll down you the page horizontal divider moves from top to bottom.

If I use PgUp/PgDown to scroll across pages, I get the page misalignment. See a screen recording: https://www.screenpresso.com/=E77a2IBKhX8T