This detection was added in Anti-Beacon 6.7.
Anti-Beacon treats this as telemetry because Sentry is an application monitoring and error-reporting service. Sentry describes itself as an “application monitoring solution” for identifying and monitoring errors, bugs, and performance issues (Sentry Privacy Policy). Sentry’s API documentation for issue events shows that event data can include error metadata, tags, timestamps, browser information, and user fields such as IP address depending on what the customer submits (Sentry Docs: Retrieve an Issue Event).
Anti-Beacon blocks Sentry telemetry endpoints. This can affect error monitoring, performance monitoring, and other Sentry-backed reporting features used by applications.