When I had the same problem it was the throttle body butterfly sticking shut.
I gave it a clean, but rather than filing it, I noticed that the flap was touching one side of the body more than the other. So, I used a flat blade screwdriver to ease the flap over a little on the shaft and it worked perfectly, in fact, it's been working for nearly a year.
As said, it's a poor design from the off. A Cheshire expat in France.
2015 RRS HSE 3.0 SDV6
2015 Aston Martin Vanquish
2010 Jaguar XFR Le Mans

Yep a really bad design.

I tried cleaning mine and ended up having to replace it. But it didn't resolve it. It was the changing the breather (c£110 part cost) that fixed it for me in the end.