It seems that on my second character I have encountered the bug where Preston Garvey can't be recruited as a companion when Taking Independence is done (I believe that's the quest related to it?). He still gives me settlement quests and I still can turn in quests, but I can't interact with him on any other level, not even to trade. This isn't so annoying since, on this character, I will be siding primarily with the BoS, but it is a bit jarring to see a glitch/bug popping up in an otherwise spotless experience.
Note: I have the game on PS4, so I cannot mod myself out of this situation.
Any advice? I did Taking Independence quite a long while ago, now, so it would be counter-productive to the rest of the game if I reloaded a save from that time frame.