Yes! Acquia Support will investigate site issues, even if you are using an EOL Drupal version.
For issues directly related to that EOL, and/or related to code that should be upgraded, the scope of support may be limited to recommending an upgrade.
Don’t panic: Drupal 9 won’t stop working in November 2023. The most important thing is to have a viable plan to upgrade as soon as possible. And if you won’t make the Drupal 10 deadline, you should prioritize applying all available security patches to your Drupal 9 site (currently 9.5.11).