Yes, please post pic so we have a better idea of what you're confronted with. Just a guess but perhaps you had stepped BOs which can present their own challenge, and for some, create an uneven line when picking up sts to seam. There's a way to work BOs so that they create a soft curve or clean slope so seaming is much more even. Again, just a thought.
ETA: sometimes, on areas with COs/BOs the wrong sts are picked up for seaming so a ragged line is created. You might check here
to see the diff between when the right sts are used vs the wrong. In the chapter 'Working the Neck Band of a Sweater' note the raggedness of the the line between collar and body when the wrong sts are worked vs the one with the smooth transition. Obviously you're not doing this procedure but a visual aid perhaps (if this is along the lines, visually, of what you have).