Q: Threshold of bottom line - PDF reader & browser

A small design problem I would like to solve - does anyone know the trick?

On browser and PDF reader (edit: in File Browser document view), if I read something, I swipe up in steps while proceeding to read. Screen scrolls as it should - OK. If I swipe down and go back in the text, the black bottom line appears as it should - with menu bar on the browser or page numbers on the PDF reader.

But it mostly happens, that I, if I want to swipe up / proceed reading, make a tiny little movement in the other direction while releasing the finger from the screen.

This leads to appearance of the black bottom line despite I didn’t wanted to scroll in the other direction or wanted to do something in the bottom line. This is very annoying while reading!

So my question is -
can I modify something in the system (edit: or config file) to give a threshold of e.g. 10 pixel of swiping down (scrolling up in the document), before the bottom line appears? So that a small swipe, e.g. 5 or 8 pixel will be ignored and bottom line does not appear in this case?

edit: I want to say, the bottom line should not appear until the swipe down is more than e.g. 10 pixel.)