OSX Apple Preview app: problem with scrolling with two fingers. On my Macbook Pro in Preview, the scrolling is buggy. Two finger scrolling will only advance to the next page, not move lower [or higher] within the same page.
In System Preferences, most trackpad settings are off, including Swipe between pages. Only Tap to Click is on.
Video attached. In the video, when you see a page ghost appear, that's when i move two fingers on the trackpad. If the cursor moves, that's one finger. So i cannot use a two finger scroll gesture to move the page up or down.