Was doing Seaside Descent for Whispers. The first objective is to kill all enemies in the first area. Found the barrier to the next area quite quickly, noticed a Treasure Goblin icon on the other side, where I couldn’t yet get to him. Shrugged and went on killing things. Cleared everything, including a random Butcher spawn. Now the objective says there’s one enemy left… And the only thing on the map is the Treasure Goblin on the other side of barrier where I can’t get at him. Been around the first area a couple times and haven’t seen any more red dots. I’m thinking it has to be the Goblin. Enemy types are skeletons, nothing that might fail to spawn (like ghosts).
This happened to me today on PC. I cast frost novas all around for a while thinking it was something stuck in stealth or glitched into a wall… Then I saw that goblin mocking me from beyond the barrier. They really shouldn’t count toward completion.