Steps to reproduce -
Fight an NPC (As a Mage)
During the fight press Vampire Bite.
Vampire Bite will give the feedback "You prepare yourself to bite on your next melee attack"
Break away from casting spell to attack an NPC with a melee attack.
Expected result -
Bite on your first attack
Actual result -
No Bite on the first attack. Only the second attack.
Misc Notes -
So far, I never bite on my first melee attack, only on my second. Which wouldn't be a problem if you had 4 APR.. But I play a Mage, so having to hold out for that second attack to bite is dreadfully slow.
This seems to be relatively new, as I've never had the issue.. or.. Never noticed the issue as I'd never needed to target a particular HP before the Vampire Bite update to "Infect" an NPC.