I subscribe to a YouTube channel, MurderMysteries (no space), that has more than 300 episodes of British T.V. series.
Here's what you can watch:
Inspector Morse - 33 episodes
Inspector Lewis - 34
Doctor Blake Mysteries - 44
Sherlock Holmes w Jeremy Brett - 42
Sherlock Holmes w Basil Rathbone - 13
Sherlock Holmes w Matt Frewer - 4
Maigret w Michael Gambon - 12
Vera - 40
Cracker - 12
P.D. James - 36
Agatha Christie's Poirot - 77
Cadfael-13
plus more.
Plus there are some full length movies, Edward G Robinson, Alfred Hitchcock and others.
If you're interested in these shows and you don't have Britbox or Acorn, you can watch many of them here.