@Melissa2784. Hi Melissa, that is terrible and no host should be using the same code for any two guests. Just checking you were a guest and not the property owner?
If its a smart lock door code these can be generally be changed remotely in an instant (assuming you have wifi at the location to update the lock). When we issue a guest door code it is for a temporary period only and once the guest leaves we also delete the code from our app. If she had to visit it sounds like she uses the same code for herself as well as guests or doesnt have wifi access so had to fix onsite. Again, we have a separate code for the host, the cleaners, each guest etc so we know exactly who else might be in the Airbnb if issues arise during a guest stay (which they dont).
I would have reported it to Airbnb Safety team and found another place to stay, requesting a full refund.