Unread count only shows up for events that performed a notification
In a previous build, a room was marked with bold if there was an unread message - any message. Now this was replaced with a unread counter, but it only shows up for items that created a notification. So a Room set to "Mentions & Keywords" notification level (using Element nomenclature and setting) does not send a notification for every message, thus in Neochat there is no way to tell if there are any unread messages in that room.