Gradient Feather Tool transparent to white - not layer under it
I have a dark image that I'm trying to fade to rectangle with black fill below. When I use the gradient feather tool, instead of showing increasing darkness (exposure of the underlying layer) it shows a whitening gradient that suddenly turns black at the end of the vector. I've tried reversing the position and putting the black rectangle on top and then fading it to the underlying image, but it does the same thing.
Can anyone help me fix this?
