[Bug]: Plane continues using the initial generated hostname after assigning a custom domain

[Stacylia]

Summary

Replacing the default hostname with a custom domain during a Plane deployment does not fully update the application's public URLs. Although the instance becomes available through the configured domain, some parts of the application continue referencing the original *.sslip.io address created during deployment.

This behavior is noticeable during authentication and when accessing uploaded media.

Expected Behavior

Once a custom domain has been configured, every externally visible URL should use that hostname. The automatically generated deployment domain should no longer appear anywhere in redirects or asset URLs.

Observed Behavior

The application still relies on the original *.sslip.io hostname in several places:

• Authentication redirects send users to the generated deployment domain instead of the configured custom domain.
• Image uploads are stored with URLs pointing to the original hostname rather than the public domain exposed through the proxy.

As a result, users may be redirected away from the intended domain, and uploaded assets reference an unexpected address.

Steps to Reproduce

1. Deploy Plane from the Coolify service catalog.
2. Replace the automatically assigned *.sslip.io hostname with your own domain.
3. Complete the initial setup wizard and create the administrator account.
4. Continue to workspace creation or sign out and sign back in.
5. Observe that redirects still target the original generated hostname.
6. Upload an image and verify that the generated file URL also references the original deployment domain.

Environment

• Coolify Version: v4.1.2
• Deployment: Self-hosted
• Operating System: Ubuntu 24.04

Additional Notes

The issue appears to be limited to how Plane determines its public base URL after deployment. The reverse proxy correctly serves the application on the custom domain, but internal URL generation continues to use the hostname that existed when the service was initially created.

Both authentication flows and generated media links should consistently reference the configured custom domain rather than the automatically assigned *.sslip.io address.