Opted to start Vashj’ir questline on character transferred in from WOTLK. Completed the boat introduction, completed Sea Legs and acquired the similarly named buff. During the follow-up quest, got on a mount on the sea floor. Upon attempting subsequent quests, all mobs were evade-bugging.
I had to leave the area and re-enter Vashj’ir to actually enter combat with anything. Issue has not resurfaced. (Yet.)
Also, Blood Tap is still broken on DK.
(Edit)
Also, during questline following “Gimme Shelter” where you lead Adarrah to the Smuggler’s Scar, the fog in this cave is incredibly thick, to the point of almost being opaque.
I had a similar issue during the dream-version of the rescuing-Fandral questline in Mount Hyjal. No graphic setting changes seem to influence this issue whatsoever.