Your ads are only advertised to potential leads within your target radius set when you created the ad. The minimum radius as per the housing category on Facebook is 15miles for the US and Canada and 10miles for any other country.
From time to time, you may receive leads that are outside of your desired advertising radius. This can occur when a lead has travelled to the location you are advertising and has seen/clicked on your ad while within that radius.
It's important to understand that a lead outside of your advertising radius doesn't necessarily mean that the lead is not interested in your services. These leads are still valuable and worth pursuing:
They maybe located just outside of your radius and searching for properties within your area of expertise
They maybe considering a move to your local area within the near future
This maybe an opportunity for you to refer the lead to an agent in their local area and develop a reciprocal referral relationship with that agent
Don't ignore these leads nor make assumptions or come to your own conclusions unless the lead specifically has confirmed information about those assumptions. Deliver what was promised (a home evaluation) and start the conversation with the lead to discover what they are looking for. These leads are a unique opportunity for you, as they likely don't know any other agent in your area.
However...
If you noticed that suddenly the majority of your leads are coming outside of this radius. Then in this instance the algorithm for the ad may have become skewed to these areas. To address this you can do the following:
Adjust the ad budget by more than 25% up or down. This will reset the audience/algorithm for the ad.
Pause and relaunch a new ad.