I agree with American Redstart songs sounding like various other warbler species quite often. I've heard them singing in the east, and I think they could be something else, and they turn out to be American Redstart quite often. The Merlin App gets confused with American Redstarts too, I have heard people have recorded an American Redstart that they are looking at singing on their Merlin App, it has said it was a different species, like Black-and-white. Even if Merlin hears something, it is a good idea to try to see the bird, since it isn't always right. Also, Merlin App has issues with Indigo and Lazuli Buntings it seems like. I have recorded a Lazuli Bunting on Merlin, though it says it is an Indigo Bunting. I am sure there are lots of other problem songs, and of course Northern Mockingbirds doing a lot of different birds.
Brandon Percival
Pueblo West, CO