I've only seen this in Huons cos thats basically what I hunt. I will often (say 5 times in a 3 hour hunt) see a huon spawn in the open and be marked unreachable straight away. There is no chance it has tried to attack something so it should not be in this state. If I get close to it I can sometimes agro it onto me and then I can hit it. But the problem is I start taking hits for all the combat. I am not able to tag it from a distance and reduce my armour/fap decay. THe alternative is to stay away from it which kinda screws with my hunting as there is an area of the field behind it where I cant tag mobs. So its a bit of a pain in the bum. AS far as I can tell the mob is eventually removed from the field which is a little strange in itself. I guess there is some sort of routine which cleans up mobs that have been unreachable for an extended period.
I've seen this with the northern most Feran flocks too. Either spawning under a tree and stuck, or sometimes unhampered in midair.
This sort of thing also seems to happen with the carabok puny in the academys, I'd just thought someone had left it when I saw it before, but it is most likely the same issue. (no-one else was around at the time)
