There has to be some kind of exploit/cheat to see where people are

@Peri_Longbow_plz If you are on PC there is a thing called wall hacks that shows the enemy where you are. As far as I know this doesnt happen on console.

Without video tho we have no idea what happened. Perhaps you moved and swapped items and that little bit of sound drew them to you because as you mentioned they were close. Then once inside the building an experienced player might know the rat spots they will find people.