[COMPLETELY VANILLA SAVE] Many Nuka-World NPCs are completely busted and I can't talk to them... and I don't even have UFO4P

I'm on Xbox Series X and have been playing this vanilla save to get every achievement before moving on to a modded second playthrough, my total playtime stands at 6d 21h 37m.

I however seem to be running into the worst possible glitch for my scenario, multiple NPCs in the DLC either cannot be talked with in the slightest or repeat the approach dialogue ad nauseum.

Mackenzie, NIRA, the rest of the Traders, Sierra, Shank, two of the Hubologists (surprisingly not the ones for the quest or Zeta Alignment), and worst of all CITO HIMSELF.

I have looked EVERYWHERE for a solution, and the only things I have seen are UFO4P breaking the game or fixing it via console commands.

I have never had UFO4P installed, nor do I have any other mods, hence why I have been able to earn achievements in this save.

I am also on Xbox, so I can't change the NPC flags to fix it manually, and I can't do cheat terminal because, THAT WOULD DISABLE ACHIEVEMENTS.

So I'm just completely stuck here.

Please for the love of god help me.