I’ve started watching ‘Line Of Duty’ and added it to my Watchlist, but it’s missing from my Up Next section. I only have one show in my hidden (dropped) section, and that’s not it. I’ve read in the forums that shows that have finished may not show up, but I have ‘Homicide Life On the Street’ in my Up Next section, which has also finished. So I’m not sure what I’m missing?
when you say “you just started watching” and “added it to your watchlist”, did you fully finished watching one episode yet? you need at least one episode marked as watched in order for it to move from watchlist to your up next. If you’re in the middle of the episode, it’s not going to show up until that first episode you watch is complete and marked as watched. Just adding it to your watchlist, doesn’t mean it will show up in your up next.
It looks like you do have that series hidden. If you filter your hidden items settings page to “watched progress” (see screenshot below), you should see it there. Just click on the item to restore it and it should appear in your up next/progress