UPDATE:
As I have found out, this bug apparently happens only when fighting monsters and animals, human enemies are not bugged.
Also I have managed to find somewhat of a temporary "solution" to this problem. Whenever I kill a monster I run away before it revives, so it won't aggro on me. Then I go back stealthed and shoot it with bow FROM MAX RANGE so it won't aggro on me immidietly. This one shot will make it untargetable, and I ran away again to not aggro it again. Now I can come back and monster is still there but it's not responding anymore to me, so I can safely pass.
This "solution" is really annoying, especially when dealing with groups of enemies, because you have to really carefully pick them with bow.
This really needs to be fixed ASAP.