@Anna11968
I host long term stays on Airbnb and that is what I prefer, but I am a live in host and therefore am well protected by the law because tenants' rights do not apply. These requests might not necessarily be scams. It could be that the price is attractive (either the price you have set or the fact that with new listings an additional discount is automatically applied for the first few stays or both).
However, you need to familiarise yourself with local laws around STR and tenants' rights. I have read that people do not get tenants' rights here in the UK unless they have stayed somewhere for three months, but I don't know if that's true or not. You should seek advice on that.
Also, did you know that with a complete unit you are not legally allowed to rent for more than 90 nights a year on STR and that Airbnb will block the rest of your calendar after that? If you are abiding by that law, it's really not a very viable option for renting out a property.