Rahul I checked it on your end, and here's what happens:
You have set the radius as 10km
The Google Distance Matrix is giving the distance as 14km (this is used to determine the delivery charges actually,)
But when the application sends the data to the server to validate the operational status, the server checks with GeoDistance and not Google Distance API. With geo-distance formula the distance is coming as 9.34km hence it sends the status as "operational" and the customer application allows the user to place the order.
I guess if Google Distance Matrix is enabled, then we will need to check on the server end too (this will mean two API calls one on the backend, another on the frontend) - But this could solve this issue.