From my post in the General Discussion forum, this seems to be a bug that has been re-introduced with Blackwood- from what others have said. Many times an NPC I'm fighting (this isn't specific to Blackwood location fyi) will just stop, their health bar remains the static active, but you cannot hit them... and then they drop dead. Many times I don't even notice until my Companion puts away their weapon and walks away... then I stop fighting... and the enemy finally drops dead.
CP: 1965 ** ESO+ Gold Road ** ~~ Stamina Arcanist ~~ Magicka Warden ~~ Magicka Templar ~~ ***** Strictly a solo PvE quester *****