Diesel particulate filter (DPF) KAMOKA OPEL CASCADA

Diesel particulate filter (DPF) OPEL CASCADA KAMOKA 8010066

I fitted a Kamoka 8010066 diesel particulate filter to my 2010 Insignia. The unit was installed correctly, glow plugs and sensors are functioning, and the ECU was reset as per standard procedure. As far as I can see, the filter fails to support regeneration at the conditions typically expected on this vehicle (Opel/Vauxhall Insignia 2.0 CDTI). Only sustained motorway speed driving prompts (100-110 Km's/hour) a successful regeneration, suggesting inadequate soot retention or temperature build-up - unusual for this vehicle. Is it possible that the ceramic core may have too high a porosity or incorrect cell geometry, which may be preventing the necessary heat retention during regeneration cycles? It would be interesting to see a comparison of Cell density (CPSI) and wall thickness of the ceramic substrate between this aftermarket item and the OE part.