Something i've seen happen with Ekko.

I'm a big Ekko main so this /bug/ happens to me quite a bit. I'm entirely sure if it's a bug at all but it's just something I noticed while playing him. His Ult tends to not go to it's intended placement (Where the time ghost is.) It will end up cutting the distance short. It's happened to me allot and I just though I would throw it out there to be examined.