Ekkos Phase Dive eating skillshots? Or just Brands?

So, last game, playing as Brand, I started noticing that several times I would die to an Ekko jumping on me. Now this isnt a problem in itself, what WAS a problem was that my Sear never stunned Ekko. Its didnt travel its full distance either. I started wondering "Did it hit a minion maybe?", "Maybe he wasnt ablaze?"

So I started looking really hard whenever he went for me, and came to the conclusion, that even when I cast E first, then stun, when he used Phase Dive, the Q would stop short, seemingly do no damage, and not stun.

People keep saying "Well its like flash", but then why does the Sear not travel its full distance? In fact, it stops right where Ekko is in his animation at the time. It happened repeatedly, because due to the range on E, the second part of Phase Dive would practically always go off right as I cast Q

So, has anyone experienced this? Is it all skillshots or just somehow Brands that are affected?