Barking at gate

So Beau is still a problem with my birds and we keep him gated in the kitchen area when I cannot watch him in another room. Problem is going into and out of the kitchen. He is usually fine with me, I give him a sit and wait and then throw a treat. But other people, he goes nuts jumping and barking. Sometimes he is fine for them to enter and exit with sit/wait/treat and other times the second he gets the treat he goes ballistic.

Not totally sure how to deal with this. And he goes particularly ballistic if he hears the sound of our creaky stairs toward the birds.