Same to me. My level is 48, playing on Highest difficulty. Behind the Hightower H6 in Arroyo I found a group of 6th Street gangsters and attacked them, but deal no damage. No damage with pistols, with SMG, with bleeding, with fire damage, with gorilla's hands and so on. No cyphers around them, including zero.
I tryed to change difficulty level, checked all previous saves - nothing helped. PC.
I tryed to change difficulty level, checked all previous saves - nothing helped. PC.