Illaoi E gets caught on certain abilities

Illaoi's Test of Spirit seems to be getting blocked by other enemy champion abilities. For example, I can't use it through MF's Make It Rain, Mini Gnar's Boomerang, or Kha'Zix's Void Spikes. If Test of Spirit and those abilities collide in midair, it treats those abilities and projectiles as if it's hit a minion.