So, not sure if this is something I can recreate but it has happened several times now.
When I jump up and launch Alani’s ultimate at someone randomly the ultimate will just vanish on contact. I’ve seen it happen on Miko and know it was this bug, but I am pretty sure I saw it happen to a different character before so my theory of Miko throwing their Ultimate and the Miko head detaching seems debunked.
Summed up. Some times Alani’s ultimate literally vanishes entirely when hitting an enemy player.