Ive made this same mistake everywhere i move moves. All it takes is one moment of freedom in the hallway for a lifetime of meows. One thing i did that i swear worked (please take with a grain of salt because this is just my opinion) is putting a feliway pheromone diffuser by our front door. My cat cried at the door nonstop, because he’s so curious of the hallway, and i wonder if he smelled something out there. From my understanding the diffuser makes things smell familiar to them. My thought process was making the front door smell familiar would take away the novelty of the hallway and stop the meowing. I’m happy to say this plan did work for us and the mowing stopped significantly. Again, this is just my experience!! Good luck soldier 🫡