If you weren’t scared of the dogs in the first place, they wouldn’t react to you. It sounds to me like the moment you meet a dog, you expect it to be hostile, and go into fight-or-flight mode. The dog picks up on your pheromones and responds in kind. But it isn’t really about the dogs.

You give yourself away in your opening paragraph where you are incredibly patronising about your white ‘friends’ “ The really good ones have a Black Lives Matter T-shirt lovingly shoved into the back of a drawer somewhere.” Sarcastic, much? You are basically convinced that these people are still racist at heart, so you’re never really confident around them, and the dogs, who see past the facade and are not bothered by social niceties, react to your unexpressed but real hostility to their pack/family/owners.

A poorly-trained dog will get up to all kinds of things. A guard dog will guard, and so on. You can expose any dog to any number of people of every ethnicity under the sun. The results will be the same. The dog will be friendly and comfortable around those who are really friendly and comfortable around their people.

I cannot and will not blame any person of colour for disliking white people. That would deny the reality of the situation. But until and unless you can bring yourself to actually feel comfortable around white people, then you’re going to have to avoid the ones who have dogs.