I’ve been noticing this for a while, but put off filing a bug until I could confirm it wasn’t just temporary or a user issue.
On the Android app (might affect iOS, I don’t know) when the mark-read-on-scroll option is enabled, it works normally until something causes the list to refresh. This happens when Intelligence Training is modified, new articles arrive, or searching is edited (enabled/disabled/terms modified). The only way to get it to come back is to back out of the story list view up to the feed view, and re-enter the folder story list view.
It’s super annoying in the case of searches. I’ll frequently go into my “headline news” folder of stories, and search for a specific term that’s very popular at the moment. I can quickly skim thru the results to get them all marked as read (since the content is highly redundant), which is the only available way to bulk mark articles as read within search results. However if I’m doing this in the middle of the day, it’s very likely that one of the feeds will add a new article on the popular topic that meets my search criteria and the automatic refresh of the feeds will update my article list, breaking the mark-read-on-scroll. Since “fixing” the mark-read-on-scroll requires exiting back to the list of feeds, which also clears all search filters in the story list, I regularly have to exit back to the feed list, re-enter the “headline news” folder, re-enter the search term, and scroll back down to where I left off.
It also gets difficult when simply scrolling thru a very long story list. During scrolling, the different feed sources populate on screen at slightly different rates, so the list will jump around a bit on scrolling normally. If the sources update in the background and new stories are added to the top of the list, it’s indistinguishable from the normal scrolling behavior but causes the mark-read-on-scroll to abruptly stop working.