Camille vs Cass

So Cassiopia's W (Miasma) is suppose to make it so no mobility spells can be used. Camille, however, can still use her E during it to latch onto walls. I thought "Hey, maybe since the skill itself isn't moving them and she just gets dragged along if it hits a wall it works." So I tested this by using Nautilus while in Miasma since his Q has the same properties but I wasn't able to use it. There's either some kind of inconsistency (which is horrible for the game) or just a bug (also bad but not as bad as being inconsistent) that allows Camille to use mobility skills while grounded.