what's going on with post titles - inconsistent in showing read / not read?

When I click on the title of a post (I use list view) to see the comments, and then go back to list view, the text style of the title is no longer indicating that I have visited that post. It still shows a change when I upvote or down vote the post. It used to show a change when I followed the actual link (url), but that went away weeks ago. Why all the changes? I'd prefer Jerboa to indicate that I have seen a post if I interact with it in any way. That is, I would expect that clicking the url thumbnail, the title text, or one of the arrow buttons would mark the post as 'seen'.