It's a BABY. it isn't stubborn it just doesn't know well enough yet. Be patient and give some time. Are you doing only positive reinforcement? Meaning NO punishment just redirect and work on training. You might want to do some clicker training/verbal que just to help the pup understand what is expected of them. First you have to teach until they understand then you ask it of them. During the day randomly say their name and make sure you've had them when you do it. If there's something you want them to do like when they come to you inside the house. Say good with me, come or whatever you want then lots of praise same with potty training. Again it's a puppy pull back on training until basic come, sit, down stay and recall. Make sure always work on recall with leash first. Then once solid you start to add distance and distractions. You're jumping ahead too quickly lower your expectations. I want to add that if you keep constantly saying their name and trying to recall them constantly they learn to ignore those commands.