Calling onTrigger() for Particles?

Hello,

i have a small scene with a particle system and a trigger shape. There also is a dynamic rigid object.

I want to be able to detect if a particle is inside the trigger object. If i am not completely wrong i should be able to do this with a custom filter and the onTrigger() callback function. However, if the dynamic rigid object touches the trigger, onTrigger() is called, but when a particle enters the trigger shape, it is detected by the filter (i can see it when i set a breakpoint inside my filter shader) but the onTrigger() callback is never called. (How) can i fix this? Or is it impossible at all to get a trigger callback from a single particle?

This is my filter shader:

PxFilterFlags ParticleFilterShader(
	PxFilterObjectAttributes attributes0,
	PxFilterData filterData0, 
	PxFilterObjectAttributes attributes1,
	PxFilterData filterData1,
	PxPairFlags& pairFlags,
	const void* constantBlock,
	PxU32 constantBlockSize)
{

	pairFlags = PxPairFlag::eCONTACT_DEFAULT;

	if(PxFilterObjectIsTrigger(attributes0) || PxFilterObjectIsTrigger(attributes1))
	{
		if ( (isParticleGroup ( filterData0 ) && isTriggerGroup ( filterData1 )) || (isTriggerGroup ( filterData0 ) && isParticleGroup ( filterData1 )) ) {
			pairFlags = PxPairFlag::eTRIGGER_DEFAULT;
			return PxFilterFlag::eDEFAULT;
		}
		/* When i use only this, without the check above, my rigid dynamic triggers the callback.
		* pairFlags = PxPairFlag::eTRIGGER_DEFAULT;
		* return PxFilterFlag::eDEFAULT;
		*/
	}

	return PxFilterFlag::eDEFAULT;
}

And this is my onTrigger() (it does not do much at the moment…):

void PhysXConnector::onTrigger(physx::PxTriggerPair* pairs,physx:: PxU32 count) {

	for(physx::PxU32 i=0; i < count; i++) {

		if (physx::PxPairFlag::eTRIGGER_DEFAULT) {

			PxFilterData filterFlags0 = pairs[i].otherShape->getQueryFilterData();
			PxFilterData filterFlags1 = pairs[i].triggerShape->getQueryFilterData();

		}
	}
}

The PhysxConnector Class defined like this:

class PhysXConnector : public physx::PxSimulationEventCallback {

		/* Other private functions * /

		public:
			/* Other public functions * /
			void onConstraintBreak(physx::PxConstraintInfo* , physx::PxU32 ) {  }
			void onWake(physx::PxActor** , physx::PxU32 ) { }
			void onSleep(physx::PxActor** , physx::PxU32 ) {  }
			void onContact(const physx::PxContactPairHeader& , const physx::PxContactPair* , physx::PxU32 ) { }
			void onTrigger(physx::PxTriggerPair*,physx::PxU32);
			/* Other public functions * /

	};