Vanish has a bug where you vanish but due to latency issues, opposing players can still hit you with snares such as garrote AFTER you've vanished. The snare gets applied and overrides the speed boost gained from vanishing causing the player to basically stand there, unable to move and resulting in being instantly found and killed.
Because latency is the problem, the simple fix is to apply 1 -2 second immunity to snares (not mezz) after using vanish.
Because latency is the problem, the simple fix is to apply 1 -2 second immunity to snares (not mezz) after using vanish.