Dead bodies of enemies

When I kill enemie body react as it should be but after I go out from this locatio and go back it become like this:

i used to have them dying properly, but it’s been a while that the majority of them end up like this after exploding, also some of the worm just end up AFK & already dead in a straight line right under it.

There’s another ennemy with AI glitches, the siren in the sewer sometimes just goes AFK and stay in the middle of the water, not moving at all, if i manage to kill it, the small one coming out of it will fall back to the dead one position and go AFK too.