migrating runner-scale-set by uninstall and reinstall helm release removes newly registered runner group

Checks

• I've already read https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners-with-actions-runner-controller/troubleshooting-actions-runner-controller-errors and I'm sure my issue is not covered in the troubleshooting guide.
• I am using charts that are officially provided

Controller Version

0.8.3

Deployment Method

Helm

Checks

• This isn't a question or user support case (For Q&A and community support, go to Discussions).
• I've read the Changelog before submitting this issue and I'm sure it's not due to any recently-introduced backward-incompatible changes

To Reproduce

1. Follow the official guide to deploy `gha-runner-scale-set-controller` and `gha-runner-scale-set` `demo-runner-group`

2. Set up a new cluster (environment) for migration testing, deploy `gha-runner-scale-set-controller` with the same credential.

3. When `demo-runner-group` still have several active runners, uninstall the `gha-runner-scale-set` `demo-runner-group` helm release from the old cluster.

4. Install the same `gha-runner-scale-set` `demo-runner-group` helm release in the new environment.

5. New actions begin to use the newly registered `demo-runner-group`, nothing is wrong here.

6. Wait for the old runners finished building, and the newly registered runner group is suddenly removed from the GitHub runners settings view.

Describe the bug

Newly registered runner group got removed by the controller when migration.

Describe the expected behavior

Newly registered runner group does not get removed by the controller when migration.

Additional Context

Not available.

Controller Logs

Not available.

Runner Pod Logs

Not available.

The payload names no source files, tests, or controller entry points. Start by reproducing the documented Helm uninstall/reinstall migration sequence with active runners, then trace the controller behavior when the old runners finish. Done means the newly registered runner group remains present after migration; controller and runner logs are needed to validate the result.