What rendering intent are you using? I would recommend Perceptual for a matte black, not relative.
Relative seems to make the blacks muddy and many times way to dark, less shadow detail.
Not to offend, but I don't know the R2400, I am assuming you are selecting Matte black, as photo black can sometimes
create the effects you mention when printed on a matte paper.
Epson Enhanced matte is one of their standards, if you can't find a profile I would try calling Epson and see what they
say. Depending on the inkset of the 2400, you might be able to use a different profile i.e. one for a larger Epson that
has the same ink set.