I have noticed the same about dogs. When I got a blind date with the girl I later married, she had a small protective dog that had driven off several suitors. When I knocked and she answered the door the dog flew at me snarling and growling.
Suddenly it stopped put it’s butt on the ground and looked at me with this “HI! I LIKE YOU!” look on it’s face. From that moment on the dog and I were the best of friends. I also married the dogs owner. Best thing I ever did. 49 years of bliss till my wife passed away.
Woman answers the door for our first date with her small white dog. I knelt down and played with it for a bit before talking to her. She later told me the dog didn’t like men, so she decided she’d give me a longer trial run. While it didn’t work out (the dog was saner), we’re still friends more than 25 years later.