@dan your link, only have my iPhone at the moment, when I first load the page nothing works, then swipe works, then the arrow works once, then if I swipe and select arrow jumps back to start image, then after swiping and selecting arrow it all starts to work, so for me over time is works but not for the first 1-2 minutes
See my comment to another thread. For me, it seems if all the thumbnails are on screen, clicking on a photo shows the larger image and navigation by mouse or keyboard works fine. Making the browser window less tall so some of the thumbnails are off the bottom of the screen breaks the navigation. Making the window tall again and all works fine