While not actually seeing your frames, I would have to guess.
Did you have the frames all shoved together, if a gap between they will build out/fat, were these new foundations, they will sometimes build out/fat on one and leave the one next to it shallower.
Sometimes they will bulge out in places and be shallow in other's on the same frame.
They will "usually" build more even comb on the second time around using the old comb.
Many things can happen, remember bee's don't follow human rules, they will do as bee's do !
Remember to take all information on inter-net boards with a grain or two of salt.
PCM