This has been something we’ve wanted to address for years now (the original internal issue is from 2019).
Basically we don’t want to create watch history for views that are not organic, with the addition of the Discover activities this just became more important as most of the time you’re not manually marking something as watched on your server because you’ve just watched it, so that history would be inaccurate.
Others have been complaining about this too: Plex Dash history "wrong" when marking items "watched"
