I want to know why I still see errors from health check endpoints after enabling the health check inbound filter.

The health check inbound filter only drops matching transactions. It does not filter out error events that occur on health check endpoints.

If you also want to prevent those errors from being sent to Sentry, you'll need to filter them separately. You can do this with an error message inbound filter or directly in the SDK using ignoreErrors or beforeSend.

For more information, see the inbound filters documentation.