I noticed another bug with Negate. It doesn't always negate the ground effects under it.
When a Negate Magic follows a player, it is still technically placed in the same spot that the player marked on the floor. Only the visual of the purple bubble follows the player around, not the effects.
This causes the invisible Negate issue, because a spot on the floor might be Negated but you cannot see it because the Bubble visual is following the caster.
Can others confirm this?