Hi, I'm new here and I am hoping to get some help from experienced handlers/trainers here.
My Malinois pup is now six months of age. I've been trying to build up his prey drive using tugs of various sizes and a bite rag.

He was very prey motivated when he was around three months of age till around four months. He'll ignore things that is happening around him just to be able to get to the prey item. One problem even at that age of 3.5 months of age, he is very people aggressive. Tried him out with a friend sitting on a bench, not minding the pup. I walk towards friend, some 10 meters away he'll pull very hard towards that person and upon reaching will actually bite him all over at that young age.
After that incident, I've kept him well clear of people as he will pull towards joggers, people walking, even away from him.

He has calmed down as he aged, now just 6 months. I cannot sustain his prey drive for long, maybe around 2 mins and his bite will be rather weak, and the prey chasing slows.
He'll not focus on a moving prey which I'm creating but turn towards people that may be walking by some 10 meters away.

What sort of problem do you think I'm having, is this a training problem with my prey building or is it a temperament problem that the dog is having.

Thank you so much for your help in advance.

Sincerly
Bernard