Sad episode you recall.

Midsomer Murders and Miss Fisher on now, but can't compare.

I second the Foyle's War series, wholeheartedly. Michael Kitchen and Honeysuckle Weeks have such good chemistry. Not romantic, just great buddy chemistry and the storylines are just fantastic. I would also like to offer up River, with Stellan Skarsgard and Nicola Walker. Quirky, but very well written, and the acting is superb. Vera and Shetland are good. Not as sure about Shetland since DI Perez character has left, but the first few seasons are good. I also like Mcdonald and Dodds. McDonald and Dodds is a little more light-hearted on the surface, but the acting is good and the plots are well-written. There's always the Agatha Christie series, Poirot and Miss Marple. More comedic but still a good series, is New Tricks. Lots of comedy, but I like the idea of retired cops clearing up cold cases. There's one I'm still making my mind up about called Grace. It's from the creator of Endeavour. It has John Simm from Life On Mars, (another series I enjoyed,) first few seasons were pretty good, but the newest season is a little uneven imho. I'd be interested in any suggestions you have for British mysteries. We watch Britbox, PBS, and Acorn pretty much these days instead of the regular TV channels. Oh, if you get the chance to watch the Magpie Murders from PBS--it was terrific!

Adrian Scarborough who was on Ring Out Your Dead on Midsomer.

Adrian Scarborough is so good! He's played so many supporting characters in other shows it's fun to see him as the lead. Wish we got more shows per season. I also liked Recipes For Love and Murder on Acorn. The books were fun, too. Hope the series comes back.
That also reminds me of Murder In Provence on Britbox. Has Roger Allam from Endeavour and Nancy Carroll from Father Brown. More cozy mystery, but good acting. Not sure the series is returning. I also liked Madame Blanc. The first episode almost turned me off the series, but the subsequent episodes were fun. The characters were quirky and I enjoyed the scenery.
We've been watching Endeavour. I'm re-watching the series, but my husband and son are watching for the first time. Such a good series. Loved how Endeavour told the backstory for Morse, but really kept the flavor of the original series. James Bradshaw, the actor that plays Dr. Max DeBryn, the coroner, tickles me each time with his puns! Shaun Evans and Roger Allam have such a good rapport as Morse and Thursday. It will be sad to come to the end of the series once more.

Or PBS Passport. The three series are scattered over a couple of services

You might try Grace. This last season is uneven, but the first few seasons are good. Take care.

I wish it was on Britbox