We don't allow no growling at meal times. Our male can walk over and just take over the female's bowl of food, she just steps back lets him. so, what I did was separate them and stay with them the whole time they eat and I do not allow the male to come over and eat or stop her or make her go away.
when they were little puppies, we just put her and her bowl of food in her crate and shut the door and so she could eat at her own pace and not be bothered.
You might have to do that with yours. Separate them way apart and stand by the one that needs protecting. Or shut them in a crate to be protected.

WE had trouble when our male dog was operated on when he was 2 years old. HE would growl at the vet and men after that.
He never did that before. I read that sometimes they come too while being operated on or after it was done and they see who it was doing that to them and they don't like them as they associated with pain and what they went through.

Well, he is a cutie and cute face and people just want to lean down and pat him. He would growl and I was afraid of him nipping someone in fear. So, I worked on him. I would give the person a treat but I would put my hand right down there with the other person's hand tell him its okay and pat him and love him up and reassure him that its fine. He also watched his sister who loves people and soon after me working on him with treats and patting him and my hand down there, he knew it was safe because I was down there too. Now he no longer growls and actually now goes to some people.

It takes a long time, keep working but always be there and have your hand with your neighbours hand and keep popping treats that your dog loves. And talk and reassure your dog too. Maybe ask your neighbour for something with his scent on it and put it in his room he stays in and let him get used to the scent and see if that will work.

We have had that problem with our female dog with other dogs. She doesn't always react the same way though with other dogs. She is scared of big dogs and especially big puppies that gallop towards her. We went on a socializing walk with other people and their dogs and found they are all the same, they don't like certain dogs, their personalities clash just like people.
Its up to you to learn how to control you dog and get by safely.
We will tell people ahead of time when we see them coming to us that our female dog is not good with other dogs but our male is fine with them. Most people all smile when they see our female growl and do her jaw snap. Then she can go by and be so nice.

We asked this dog trainer what to do. And we use the words, NO BARK when she does her whining scare cry and growls. And we also as the dog comes up tells her to LEAVE IT and pull her along.

And if she is actually using her mouth on the dog, that is extremely dangerous and you will have to do like many other dog owners and put on a muzzle on her.

If you can afford it, hire a really good dog trainer and get help with your dog's problems.