Yeah, I saw this when testing with stars. At least for me, the only star that reversed the circle of illumination was Wolf 359, the rest act normal, like they should. I guess this one could vary. I'll have to check the other stars to make sure.
Edit: It appears that stars with a really big habitable zone (where it requires a planet or moon to be really far from the star), it flips the shadows. If you move a planet/moon closer, the lighting acts like it should.