Q5 2010 3.0 TDI 8R

Looking for some help on a EGR issue please.

I've had the issue for the past few months but only appears on motor way driving so tested a bit more as just been travelling around france.
Driving through France so after sitting on cruise for an hours or so at 70 ish, I stop at a toll for 30 secs, set off again then get the EML on with “P0401 Insufficient exhaust gas recirculation” but no loss of power etc and everything runs fine.

I can reset it and drive around for a week, local with motorway up to 70 ish but not for a prolonged period and it not come back on.
Once back on the motorway for a long drive same thing, only pings up after a brief stop but no effect to the car.

Any one with any thoughts?

Hi Simon, did you ever get a solution to this?

My A5 does the same, reset and carry on!