Smooth continuous scrolling

I just got my BOOX NOTE AIR 3 C and am trying to learn how to use it. I've read previous posts and responses on the limitations of swiping through text documents, so I was not surprised by the way swiping a page jumped seemingly random distances. But a couple of nights ago I opened a different sample document and was shocked that swiping the page was perfectly continuous and smooth as silk, as though I was physically dragging the page. It was extraordinary! My problem was that the next day I'd completely forgotten what document it was and what app I was using, and I couldn't repeat the experience. Was it the app, the file format of the document, the Refresh settings or anything else I could think of. But now that I know it's possible, it's really driving me crazy. Please help me figure out how I can get that smooth swiping joy again!