Can't loot objects (frequently - inconsistantly)

I am playing a Witch (Pyromancer). I have the unearth skill bound to my left click button. I am using WASD as my movement controls.

I frequently but inconsistently cannot loot objects on the ground (especially while in combat).

I have tried holding the left alt key and clicking on the loot text box. I have tried waiting until after combat, reanimating corpses that are covering loot and still, I cannot pick up some gear.

This is especially bad in the caravan combat in act 2 leading up to the king (who's name I've forgotten - sorry). In some cases, the corpses cannot be reanimated with the unearth spell.

I have theorized that due to the distance between me and the object (which I usually cannot visually see without text) I cannot loot it without moving. But I cannot move to the object if I cannot see it.

I have also theorized that bodies are covering the loot, however reanimating the corpses with the unearth spell should fix that, which in some cases does.