Cannot display the top page properly.

[TaisukeMorimoto55]

Description
I deployed hubs cloud v1.1.5, but it does not transition to the top screen properly and redirects to /admin. After being redirected to /admin, I get "Missing file admin.html. Please try again." message.

To Reproduce
Steps to reproduce the behavior:

1. Run cloud formation stack (hubs cloud template v1.1.5)
2. Create completely cloud formation stack
3. Access domain (which is set up on Route 53).
4. Redirect /admin
5. See error message. "Missing file admin.html. Please try again". In develop tool console, "Failed to load resource: the server responded with a status of 503 ()"

Expected behavior

1. Top screen is displayed correctly.

Screenshots

• https://{domain}/admin access errror message
  

• Checking target groups, the app instance is unhealthy.
  

• I connect to the app instance via ssh and run "journalctl -f" and get the following error log

1. Log of access to domain
   
2. Log of health check
   

Hardware

• Device: Desktop, phone
• OS: Windows, mac, iOS
• Browser: chrome, edge

Additional context

• The environment created in the same way in January 2023 is working fine.
• I have fixed the s3 permission error according to the work around https://github.com/mozilla/hubs/discussions/6049 . Other than that, no changes have been made to the template. No custom source code modifications or deployments.