Windwall interaction

When i'm facing a yasuo, it happens to me quite often, that i pass through yasuo's windwall, cast a spell, and it still gets blocked by windwall. I paid more attention to it lately, and i clearly cast the ability once i'm completely through the windwall. Is this a bug, or anything, or is this how the ability is meant to play out? if so, i would suggest changing the shape of the windwall, from a translucent screen, into a thicker wall that clearly indicates where your ability will be cancelled. the fact that you already pass a windwall means you're going in, extending, and if then one of your slows, stuns, blinds or whatever gets cancelled, it means the extending becomes overextending in a second, without you being accountable for it. pls fix this