Ok I sent Nick back to his office after I switched companions to get their perk. After getting Hancock's perk I wen't to Nicks office and he wasn't there. I also found Strong near the Boston Public Library when I know for a fact that I left him at trinity towers. I play on Xbox one so please people of Bethesda if your reading this could you please make a companion tracker or something because it's driving me crazy. Thank you.