I just wanted to share these of my puppies (11 week old and 7 year old)and the behavior i expect in all my GSD. Today my my two year old grand nephew came for a visit, he is respectful to the dogs too. They are hardly around children and yet lookie how calm both are, well all three are lol.
Once they know they have a safe place and aggression at meal time or most times, is not tolerated this can be all dogs.
I have accomplished this with all my dogs no matter the breed or age;by (as i stated above in earlier post).
Standing beside them when eating, placing my hand on them and in their bowl from time to time while they eat and hand feeding about 1/2 their food during the day. I correct all growling, ears back with verbal calm "no" and calm praise praise praise when all is good. Some dogs are little more aggressive so for them i do a little different. Your puppy isn't there yet so i won't overwhelm you with that training.
If you'll notice in the photos the ears are relaxed, that comes very quickly once they understand.
I hope you are finding some relief with your new puppy. As with most puppies/dogs, they just need to know what's expected and our job is to help them figure it out.
I just wanted to share, there is hope without locking them in a crate to feed them or giving in to the behavior...something i never do. I want my puppy to become a well rounded dog, so i teach them to be one.