It is heartbreaking, but also true that Rottweilers and German Shepherds are known to establish their own position in the family household hierarchy.
I was the main wolf, to put it lightly, he was second and my wife third, etc.
My son once unintentionally entered my space and the German Shepherd didn't like it, immediately intervening.
Luckily my son pulled back in time and came off with a slight bite on the chest. It could have been much worse.
As he grew older, the two became best friends until the dog died of cancer.
My advise: get a new Rottweiler puppy to re-establish that relationship between the child and dog.