Mine do the same thing but I actually like the ceiling looking darker.

Your using a bright white and your ceilings are not going to have as much light hitting them as the walls. When using color on walls and ceiling you often lighten the color on the ceiling a bit (25% is often stated). You can't lighten Chantilly lace or most whites enough to compensate for the difference in lighting.

Flat paint also generally looks a bit darker than eggshell or satin. If your ceilings are in really good condition you may be able to do eggshell finish and it will lighten up slightly. The glossier the paint the more any imperfections show and the horizontal plane of ceilings causes imperfections to be more noticeable.

If your ceilings are popcorn or textured the shadows from the texture make paints appear darker as well.

Torchiere lamps illuminate the ceiling, but are not all that popular today, but could make the ceiling appear lighter.

Most people expect that ceilings will be a bit darker and are okay with the combination. It gives some level of interest to the white on white look.