Why am I getting zero hints from my dad’s side of the family?

I’ve gotten more hints from my passed away illegal immigrant grandmother and great great grandfather on mothers fathers side than anything else. My dad is an American. Why am I getting no hints about him at all or any of that side of the family at all? I don’t have contact with him or any of that family either so that doesn’t help things but I’d just like to know how far that goes back and where it goes.