[GeoffR]

I've seen it happen with certain books.

I think the slow tap response compared to the fast swipe response is because with a tap the software has to check whether there is a link in the tap zone that it should follow, or else turn the page; whereas a swipe always means turn the page and so no check for links has to be done.

The books that I've noticed being especially slow are ones that have huge internal files (i.e. extremely long chapters, or the publisher has put multiple chapters in one file, or files with a very complicated internal structure that can result from automated conversions from formats such as PDF) and they get slower and slower the further you get into the chapter/file.