Fiora's Lunge issue

Fiora's Lunge targets players while their stealthed even though she has no vision on them (Pink Wards, revealing, etc.)

For example, I was managing to hit Shaco's while they were stealthed in their Q's. Teemo's stealthed in bushes (Even though I hate Teemo.) Rengar's Stealth from Ult, Evelynn before she's revealed.

In fact it almost appears as though I prioritize the stealthed targets as opposed to the visible ones.