Hello, today I tried to start the Sinnoh quest, I talked to the NPC in Lilycove and he warped me back to the player home in Littleroot. I went downstairs, talked to the NPC Mom and grabbed a drink from the fridge. When I left the home the dialogue appeared correctly, but if I try to interact with Stan the map reloads and he warps back to the front door of the Pokelab and walks back to his position.

Is there anything I can do to fix this? Can I just leave the area or will that break the quest?

I had this same issue happen to me, I just simply logged out and came right back in, problem was resolved after that thankfully.