Would you be able to try the following and see if the bug occurs? If we know what causes it we can spread the word to avoid said action.
Basically as discussed once before piper wont speak to other npcs and interview them. Im in a relationship with her and she had her last cigarette before i had that convo. I cant remember her interviewing or anything since. Doesnt even interview that uncorrupted vault in commonwealth. She also no longer smokes.
Try this.
Make her lie in a bed sanctuary hills. Walk all way past concord meuseum. Maybe go inside an interior then leave and walk back to where piper is.
Take her somewhere where she should interact with npcs and report whether she still does it.
I do suspect i could be a possible cause.
If that fails try again but this time board a vertibirs. She spawns to you. Let me know if her behaviour changes.
Normally i would test this myself but i am actuallt on an oil rigg and dont return home for 2 weeks. My absence from my ps4 is the reason i erite so many articles. Mainly boredom. I appreciate the help guys thank you