It's most likely due to a bug and has nothing to do with your hardware. It's happened to me once before down in the Tindrem sewers where a scoundrel is one floor above me and it can hit me but I can't see or hit them back.
That isn't what happened. The pathing on animals that attack was all messed up. They were getting pulled behind rocks, under the world and were put in an invulnerable state and so would not respawn. The only solution was to find the animals that were missing, tell the GM where they were and then they could handle it, but they had to be shown... It was several days of no spawns in some parts of the map and unable to complete hunt quests for several as a result.