For some reason, when I clicked in one of my Echo notification, which was pointing to https://www.mediawiki.org/w/index.php?title=Talk:Flow&topiclist_sortby=newest&fromnotif=1#flow-post-s2gcx0zvqjwnp6ct, I got blue bars on the left side of many messages, mostly messages I didn't see before. However, some of these did read before, and should not be highlighted again.