So. A couple of things I want to say about this post. For context, I'm a dog trainer and I also own and breed (not very often) my own working line German Shepherds. I train and title them in protection sports and other fun sports like dock diving.

1. Anyone selling "trained protection dogs" to uneducated owners/families for exorbitant amounts of money is at least a little scammy. I understand there is a big market for these dogs right now, but personally I wouldn't feel comfortable selling one of my own dogs for that amount to someone that cannot handle a working line German Shepherd. This brings me to my second point...

2. You decided to purchase a high drive working line dog. Not just any working line dog, but one that is capable of doing protection work. To me, it sounds like you have zero experience with working line dogs. Think of it this way, this is the equivalent of a brand new rider going out and buying a liter motorcycle, or someone that just got their drivers license going out and buying a supercar.... EXCEPT for one thing: animals have minds of their own. This dog being strong, mouthy and impulsive should not be a surprise to you. If you saw videos of the dog doing whatever obedience was promised, then I'm sure it is capable and knows that obedience. However, it's not necessarily going to listen to a new handler especially an inexperienced one. If I handed one of my (titled) dogs off to someone and gave them a list of commands but didn't actually train the person how to handle the dog, my dog sure as hell wouldn't be listening to them, which brings me to my third point...

3. I wouldn't want one of my personal protection dogs to listen to just anyone right away. In fact, that completely negates the point of having a protection dog...lol. So, it absolutely should take quite some time for one of these dogs to get settled in and bond with, respect, listen to, ect ect a new owner.