It could be a few issues. But since the noise goes away and you have just replaced them, I'm leaning towards the choice of parts. If you used metallic pads, or uncoated rotors that might be the cause. Exactly what part numbers did you use?
Also, FYI, a brake job done properly with quality pads needs zero lube to be silent.
Also, FYI, a brake job done properly with quality pads needs zero lube to be silent.