I think the path direction of some letters are wrong (in this case, probably r and p). Try running Correct Path Direction (Shift+Command+R) on all glyphs. You can select all and run it.
Glad it’s fixed. The problem was that, the path direction matters in font design (black shape should always be counterclockwise, white is clockwise). When the clockwise shape is placed with no other counterclockwise path outside, it appears black (maybe you could call it fake black path). But as soon as it’s overlaid on true black paths, it will appear white.