I don't want to get into conspiracy theory about fuels but I can 100% say when I use Tesco Diesel this happens every few runs, even on the long distance one's. However BP Ultimate and it's very rare indeed!
I now use BP ultimate whenever possible. I swear I didn't think it would make a difference and I've done it multiple times to check and it's defo the case. I can't say if any other A3 TDI will behave the same.