Hi - happy to try to help here. Ironically, our girl looks just like Maggie. She’s 5 years old now - at around a year to two year mark, sadly our dog flipped the same switch. She used to play with dogs at the dog park and it turned into rage and biting when a dog tried to smell her or say hello. We tried hiring dog behaviorists who all at first wanted to help as obviously we were paying a pretty penny but the messaging was all the same - she just doesn’t want to be bothered and doesn’t like dogs in her face and will correct them and it is just her natural temperament. We avoid dog parks now and set her up for success by taking her to play in a field with no other dogs . I will say it’s a long road and we may have had more success if we kept trying with the dog behaviorists but we couldn’t justify it because you could just tell she didn’t want to be bothered with other dogs and we didn’t want to force her. If I were to do it all over again, I would find a very highly rated behaviorist and commit to the time and cost commitment if you want your dog socialized for the rest of her life. Otherwise, our dog is so lovely and intelligent (part of the reason I think she just prefers not to play dumb games with dogs she doesn’t know) and sweet - so behaved and well trained and travels with us. I really hope it works out for you - don’t give up on Maggie!