yeah as you say, dpf regened to 0% before, but is now blocked 70+% and won't clear, with no faults recorded.
Does sound like the dpf needs removing and checking by dealer as your under warranty still, and ask them to read the egr open/close % values too ref johns159 case.
Long shot, and I know you have reduced power at the moment, but, if your regen system is trying to work, it needs the exhaust to be over 200c (iirc) to start the regen process.
This can be achieved by good blast up the motorway, keeping revs up best you can with lower gears for 15 minutes or so, see if it feels any better after that.
Edit, just seen Gus post, yes well worth it mate, he done mine, if you can send him your ecu