I've come across the same. I have a dog who gave birth at Christmas and now I'm training two of the puppies. The mom is not great with coming when asked, never

I've come across the same. I have a dog who gave birth at Christmas and now I'm training two of the puppies. The mom is not great with coming when asked, never has been. Her kids though, as soon as I whistle a certain way they show up and sit in front of me. Generally they are really good at following instructions, perhaps it's because the father is a working dog.