NPCS Not taking force from explosions

Whenever I fire a RPG at a bunch of npcs, the NPCS just drop to the ground, for me it used to send npcs flying backwards, is this caused by a update, a conflicting addon, or a bug?

If anyone can help that would be great, just as to curious to why its doing this.

Try checking (Or unchecking, as the case may be) “Keep corpses” in the NPC tab.

Garry broke it.