I have what I think is a similar issue. The 1st of the 2 "top" raft layers is the one affected. Cura simply leaves the layer partially printed. It only happens with certain parts. Also, it will not have this issue if I include another part next to it, or if I change the orientation a bit.
I attached an image of it and the .3mf file.
Partial Raft Settings.3mf