Too bad it is completely unrealistic to have humans living on Ceres the way they do, what with a surface gravity 1/6th of that of the Moon (which is already 1/6th of that of the Earth). The central premise is therefore flawed, even if they get some of the mechanics of spaceflight correct.
except for the part where it isn't flawed, it's just the limitations of budgets and special effects.
in the books the series is based on space dwelling humans have diverged anatomically from planetary humans, having longer and thinner limbs and a changed internal structure to adapt to the lower gravity.
it's unrealistic to expect a TV show to radically alter the physical appearance of every character that lives in space, so... there is a point at which being nit picky comes up against a wall of practicality.