When I use the keyboard shortcuts K and J to move the selection in the topic below, the J key jumps from the first reply to the suggested topic list at the bottom of the page.
I used J to go to the end of the topic then to the end of the suggested topic list. I then used K to go back up to the top of the topic. Once I had done that J no longer moves from the first post to the next post, it now moves to the first suggested topic on the list at the end of the topic. If I close the topic window and return to it, I have to follow the same steps to reproduce the problem. It is consistent in the topic I’ve linked to using both Chrome and Firefox (both 64-bit versions).
I’m not sure why this rather esoteric problem occurs. It didn’t reproduce in a couple of other topics I looked at including another how to. I do wonder if it is something to do with more J keypresses than were needed to get to the start or end of the items.