If you're experiencing a bug in the cagefs_enter utility that is causing autoresponder issues on cPanel servers, it's important to address this promptly. Here are steps you can take to investigate and potentially resolve the issue:

1. Confirm the Issue: Verify that the issue is indeed related to the cagefs_enter utility. Check logs and any error messages to see if there are any specific indications of the problem.

2. Check for Updates: Make sure that you're using the latest version of CageFS and its utilities. Outdated versions may contain bugs that have been fixed in newer releases.

3. Review CloudLinux Documentation: Check the CloudLinux documentation for any known issues, bug reports, or recommended solutions related to the cagefs_enter utility and autoresponder functionality.

4. Report the Bug: If you believe you've encountered a bug in the cagefs_enter utility, it's important to report it to CloudLinux. They may provide guidance on a temporary workaround or inform you of any available patches.

5. Temporary Workaround: If possible, implement a temporary workaround to address the autoresponder issue. This could involve manually disabling and re-enabling the autoresponder through cPanel or using an alternative method.

6. Contact cPanel Support: Reach out to cPanel support for assistance. They may have specific knowledge about how cPanel interacts with CageFS and could provide insights or workarounds.

7. Monitor for Updates: Keep an eye on CloudLinux and cPanel updates. If the issue is known and widespread, it's likely to be addressed in a future release.

8. Consider a Rollback: If the issue is critical and impacting your operations, consider rolling back to a known stable configuration until a resolution is available.

9. Stay Informed: Join relevant forums, mailing lists, or communities where discussions about CloudLinux and cPanel occur. This can be a good source of information regarding known issues and solutions.

10. Test in a Non-Production Environment: Before applying any significant changes or updates to a production server, it's a good practice to first test them in a non-production environment to minimize potential risks.

Remember to document any changes or workarounds you implement, and be cautious about making changes in a production environment without proper testing. Always follow best practices for server maintenance and keep regular backups of your data.