When your radio is shared on Facebook, you will notice under Statistics > Live that listeners named "facebookexternalhit" appear.
Facebook uses scrappers that are robots that analyze the content of web pages. In particular, they will analyze the content of the links you share for security reasons.
However, since a radio is a stream that is infinite by definition, there is no notion of loading as with a classic website because your radio is constantly broadcasting. As a result, the stream is constantly charging itself.
The robots are blocked trying to recover the content of the stream. This is why they are considered as listeners, because they consume bandwidth and therefore, listening hours. To solve this problem, the best solution is to wait.
You can also block/ban the URLs by clicking on the buttons to the right of the IP address of the facebookexternalhit under the “Moderate” section. 