If it isn’t often it is a possibility that it is just because all he really knows is who lives there and he wasn’t socialized properly with strangers..
My girl is the same way she has been since she was a rescue and was 1 when I got her. We hardly have people over mainly just workers like hvac, plumber, people like that. So what I do is put her in her room and when they leave she is fine when she comes out. If you need to put him in a small room to prevent him being stressed out that might be your best option. Unless you can figure out some way to get him socialized with people..
My situation is also a little different because my baby girl was abused by her previous owners . So knowing we don’t have people over, knowing her background, and not wanting to stress her we didn’t try to get her used to strangers coming over.. we couldn’t anyway because we don’t have people over haha..
Anyway I hope you figure out what will be the best plan moving forward with your little boy.
It is ok if he isn’t food motivated my girl is the same way she does however like plain boiled or baked chicken and eggs she hates every kind of cat treat imaginable and only likes one type of food for now I’m trying to work on changing that…
If you can see if he likes chicken that could become his jackpot treat and he can get it only when people come over and they give it to him.