Fetter Ward doesn't work?

[Xenosan]

Fetter ward have to be a latency problem.

Yes to this. I feel a latency hiccup with CDs and buff/debuff application compared to the UI display. Fetter Ward's is actually not even as insufferable as Purify's. If I Purify a debuff too quickly, sometimes it won't register. Even if you wait until after the visual animaton & the on-screen text display + debuff icon, the purify may not remove the debuff. Have to find that sweet spot that's waiting a half-breadth after visuals + heads-up display then use - IMO better to err on the side of caution. Because it really sucks having Purify wasted, or Fetter Warding after popping something like BotD / Perfect Balance / Raw Destruction etc than have the enemy stun stick to you regardless