If it was happening to only one razor of several then I would say that the blade might be warped, but since you are saying that it is happening on several razors then it is probably technique.
I have one razor that is out of balance from right to left. One side likes to rotate into my face, the other side likes to rotate away from my face. It shaves great as long as I remember to pay attention to my technique when using it. Some day I'll fix its balance issues.