Anxiety & Aggression with 4-Month Old

We brought home a 4-month-old male Havanese last weekend. The drive back was smooth - he slept the entire 2.5 hours.

Since then, we have been struggling. He has shown unprovoked aggression toward me, my adult son, our female vet, and her vet tech. He bit me hard enough to draw blood, and when I pulled my hand away, he was still latched on. This happened while I was calmly sitting on the floor trying to pet him. He also growls and runs away from both me and my son.

Oddly, he is completely fine with my wife, our adult daughter, and our other adult son. He follows my wife everywhere and barely leaves her side.

We have never seen behavior like this - not with our previous Havanese or any dog we have owned.

The breeder has offered to take him back, either for a refund or exchange. But I am torn. I worry about what will happen to him, even though my wife is understandably nervous given that we have younger nieces and nephews.

Has anyone dealt with something similar? I would really appreciate any insight, advice, or suggestions.

Thanks in advance.