Skewer is buggy and it will sometimes lunge but not move you forward. This mostly happens if you use it very close to a target, and it causes the attack to completely whiff.
Here is an example where I light dodge forward to close the gap of a target, then skewer at the end of my light roll. The Skewer full whiffs, even though my opponent only held W and didn’t iframe or anything. It just doesn’t lunge forward at all. It should be following my target instead of being done in-place for a whiff.