You had to be patient. It was just that the dog had to get used to the new atmosphere and the new owner. Perhaps he did not obey the commands because he did not understand that now you have become his owner. I had this situation with my golden retriever. It was given to us by people who moved to another country, and they could not take the dog with them. For a long time, he could not get used to me and my wife (he did not listen to commands and bit). I decided to learn more about this breed as Golden Retriever barks a lot
. After the reading I decided to take some advice and look at the behavior of the dog. After a while, he became a loyal and loving dog, just had to wait a bit.