My explosive weapons are completely broken. Annabelle can't kill dogs, even with a direct missle hit. Mercy may aswell shoot foam pellets. And my fatman doesn't even damage freeside thugs. I have quit the game, reloaded my save and its still the same. If I shoot at anything in VATS they just don't get hurt. If I shoot too close to me then I get injured, but their fine.
Ya it is a bug. I would do "crowd control" on a close group of Cazadors and they all would die except for one, and I would try a second attempt and he would not die.
I do normal damage outside VATS. But its almost impossible for me to get an accurate shot with Annabelle or the 40mm grenade launcher without VATS unless whatever i'm shooting at is fairly close to me.