Had a bit of a light bulb moment today with my dog.
You say your dog is okay with some dogs OP so I'm wondering if your dog's behaviour is, in part, to do with the messages other dogs are giving your dog.
We were coming towards another dog today, not much room to pass. The owner of the other dog stopped and it was obvious she was unsure so I asked if she'd like me to move out of the way so she could pass - we were standing still looking at ducks and she was walking.
She said her dog was okay but inclined to bark as he had been attacked as a puppy and could be reactive. Anyway, the two dogs walked towards each other and her dog didn't make a sound.
Afterwards, it occurred to me that I know someone else with a very reactive dog and the dog is also fine with my dog. The owner and I can stand and chat and his dog will be fine until another dog comes along.
My dog is pretty much uninterested in other dogs, apart from the odd one that makes her stop, and I can only imagine that her lack of interest and the fact that she's very calm, means that the messages she sending out to these fearful, reactive dogs means that they know she is no threat to them.
It doesn't help your situation, I know, but I just found it interesting that perhaps the problem doesn't just lie with the reactive dog but is aggravated by the way other dogs are towards them.
Whatever, the issues, focusing on you sound like the way to go.
Good luck.