I've seen where this has been fixed through PC, but can't figure out a way through XBOX ONE. Deacon, a previous companion, won't die in the second stage of the quest to take out the railroad (Already killed Desdemona). He's at one of my settlements, and every time I go to kill him it's as if he's not really there. He shoots at me, and some of my fellow minutemen shoot back, but you can't lock on to him in VATS or use grenades, missiles, weapons, etc.
I've tried doing other missions and coming back, resetting the game and console, and have sent a note to Bethesda, but no one has reached out and I'm now stuck where I'm in the game. Please help, thanks greatly ahead of time.