This is the most ridiculous thing I have ever watched. I was confused about whether the characters were British people who were living in France, I was asking myself why he was a British judge working in France not speaking a word of French, or British actors pretending to be French.
It does not work. It is absurd, but not in a funny way, believe me, I love Samuel Beckett and Ionesco, that's not it. It's like the whole posh society of London has taken over the French Riviera. I would have preferred it to be set in Great-Britain somewhere, I mean, you have beautiful seasides, there is no need to take over France. People have tried many times, it always ended badly.
The British posh accent does not work well at all, French would never sound like that unless from nobility, not even judges or High Ranked Civil Servants sound like this in French, it's so pedantic. It's not only the accent, everything is so British. You could call this series "If France would have been British". Moreover, when there is an attempt to include some cultural inputs, of course, there are stereotypes.
If you really want to watch something set in France, watch the French equivalence, Meurtre à (Add the name of a city, there are many different ones) or engrenages, anything but this.
In the meantime, please produce a DCI Ryan TV series, that will be so much more enjoyable to watch.