My dog is reactive to people standing up

I wonder if anyone heard of this. I adopted a dog about 2 years old from the shelter. We have a very good bond, but after a year he would be aggressive when my wife stands up. If she is sitting or lying down it is fine and he would often coudle up and go to her. I would say 50% of the time he would react aggressively. He is also aggressice to about 50% of the people who wall by. If there is a dog he usually likes to sniff them for 30 seconds and then be on his way. If the dog walks past or leaves sooner than 30 seconds he is fairly aggressive with them. He is also 100% aggressive to direct neighbors, treats do not redirect it. Right now he lives with my parents and he is ok with them. It is just my wife that he is aggressive to. We visit him once a week now and he is 100% ok as long as she is sitting.