Could it be a defect in the edge?
Possibly. You might have a wire edge. Try this. Run the full length of the edge lightly along a stone for a couple passes so you fully dull the edge. This is referred to as "de-stressing" the edge. Then work up a burr on first one side, then the other. Then remove the burr and progress through higher grits. You should be left with a sharp edge. If you continue to have issues after this it could be due to a number of factors. Often, though, and no disrespect intended, it seems like many problems are from improper sharpening. Either the edge needs to be de-stressed or there's a bit of a burr left, or some other problem, making sure correct sharpening is performed is absolutely crucial.