I subscribe to a number of paid streaming services (Acorn, MHz, Paramount+, BritBox, & Peacock), and also use some ad-supported services as well (Tubi, YouTube). We have 3 Roku devices (as well as a Firestick), and most services have a provision to somehow 'mark' a show as having been watched previously. This is usually a colored line at the bottom of the icon for an episode or movie. I enjoy this service because I often move around and binge-watch a number of episodes of one show, then return later to pick up where I left off on a previous show. However, a number of times I've returned to watch more episodes and found that some 'marks' were no longer there. I've tried to determine if it makes a difference which streaming player I had used before, but can't seem to make a correlation.
My question: is this viewing history (or 'marks') somehow kept in a specific player (as a cookie or something?) or is this mark generated by the streaming service and 'things happen' as being the reason that shows are either marked erratically or disappear after a while? Does anyone know? Thanks!