One of my students just submitted his first bug report to Wolfram. I’m so proud.
This is arguably not a bug, but it’s certainly unexpected, nonstandard, and undesirable behavior. Wolfram Alpha is calculating the norm of a vector as the square root of the sum of the squares of the vector’s components (i.e., the usual Pythagorean relation). But when the vector has complex numbers, that’s not the right thing to do: you have to use absolute squares. Otherwise, you get absurd results like these, and your norm isn’t even a norm.