If it can scan and read codes and data of the vehicle it should have the usual VCI bluetooth connection. If you have internet connection still within your update period, gone into the VCI manager and checked if your VCI firmware is at the latest level? I'm not sure but , but even some important coding and programming of some makes require the provided USB cable be used between the VCI and the tablet. I think I would try that before giving up.  After trying the USB cable  you may have to re- pair your Blue tooth VCI  back to your tablet again.

  If you can read fault code from the ECU that means your tool is connected to the VCI there is no problem..........You need to check other things.........If you have NO any fault code than why would you want to perform DPF regen..............On this model the EGR valve and the injector on the exhaust are very common so worth having a look at it.........