Hello, sorry if i have any typos or something, english is not my main language. I have a 2010 opel insignia sports tourer 2.0 118kw diesel engine. I have issue, when trying to start moving from parking spot or somewhere without pressing gas, the car wants to stall (it hasnt never been a issue, started doing it about a month or 2 ago) when reversing without pressing gas, then it stalls. But for example, driving on the highway, i dont see any problems. Acceleration is great, doesnt have any issues. I usually drive every morning around 35km to work (around 20min drive) with rpm around 2200-2300 and that should be enough to clean the dpf while driving. I asked my brother what could be the issue, since dpf should get cleaned by driving on the highway. He told me that it could be something about fuel injectors or fuel pump and told me to contact a mechanic who can do diagnostics. I decided to ask it here first.
Oh forgot to add, when starting up the engine. Cold or warm, there are no issues. Works like a charm
Take your brothers advice because Opel has not been sold here in the US for years .
And there are not a lot of small direct injectjon diesel engines sold in the US either… so not a ton of expertise on this site.
You could find an Opel forum, ask there. But I’d take it to a mechanic, ask around to find a good one.
Just a thought, but @Rometk if you find out more, c’mon back and post. We haven’t had a lot of posters outside of the US and Canada, but we have had more international discussions lately. We have one going with someone from Egypt now, as a matter of fact. Your info may come in handy some day. 
The Opel Insignia is the Buick Regal in the United states. The same diesel engine was available in the Chevrolet Cruze.
The symptom sounds like it is running too lean at idle. If so, either too much air is getting into the engine, or not enough fuel. You’ll need to find someone w/some basic diesel diagnostic expertise on this one.