Cause
This may be because the built-in service discovery feature of Managed Service for Prometheus collects metrics for your application.
The service discovery feature of Managed Service for Prometheus includes default service discovery, ServiceMonitor, PodMonitor, and custom service discovery.
After your application is connected to Managed Service for Prometheus, default service discovery is automatically enabled to collect metrics from the application.
To enable ServiceMonitor, PodMonitor, and custom service discovery, you must manually add and configure them.
Then, metrics are collected based on your configurations. This may cause additional fees.
Solution
To stop the billing, you can disable the corresponding service discovery.
For information about how to disable service discovery for a Prometheus instance for Container Service, see Manage service discoveries.
For information about how to disable service discovery for a Prometheus instance for ECS, see Manage ECS service discovery.