I'm playing single player, the latest patch on steam. Not sure how this comes about, but I've had enemies just walking in the air (out of range of melee attacks as well). Maybe they spawn on top of a tree and just never come down? They don't clip with obstacles such as the edge of the area. I managed to kill some of them with ranged spells, and their loot also seems to drop (and be stuck) on the same vertical height. 2 screenshots below.
Been playing since Din's curse, and I really like the spellblade subclass in this one. Thanks, and keep up the good work!