About 14 hours ago, we deployed a hotfix that should have addressed Vanish.
Basically, Vanish should cause enemies to drop target, and we had a bug that was preventing them from dropping target. We fixed the bug.
There are still intended conditions in which enemies can “see through” Vanish, of course. (Example: the Bloodhounds in BRD)
As this hotfix required server restarts to take effect, we expect that it is now working as intended on realms in the Americas, and will be picked up with maintenance tomorrow in Europe.