actions-runner-controller: webhook server: "cache contained , which is not an Object" when handling check_run event

Describe the bug When receiving a check_run event, the webhook server throws an error, which states the following:

ERROR controllers.Runner handling check_run event {"event": "check_run", "hookID": "xxxxxxxxx", "delivery": "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx", "checkRun.status": "completed", "action": "completed", "error": "cache contained <nil>, which is not an Object"}

Checks

• My actions-runner-controller version (v0.19.0) does support the feature
• I’m using an unreleased version of the controller I built from HEAD of the default branch

To Reproduce Steps to reproduce the behavior:

1. Follow the install guide
2. Configure the Helm chart to start the Webhook server, expose it
3. Create a webhook in GitHub to listen for check_run events
4. Run a workflow to trigger an event
5. Observe the error in the Webhook server’s logs

Expected behavior I’ve configured a HorizontalRunnerAutoscaler to scale on a check_run event, so the expected behavior is for a new runner to be spun up.

Environment (please complete the following information):

• Controller Version: 0.19.0
• Deployment Method: Helm
• Helm Chart Version: 0.12.7

Additional context I’ve authenticated via an app with the following permissions:

Actions (read)
Checks (read)
Metadata (read)
Self-hosted runners (read / write)

This is the runner configuration I’m using:

apiVersion: actions.summerwind.dev/v1alpha1
kind: RunnerDeployment
metadata:
  name: senteca-runner
spec:
  template:
    spec:
      organization: senteca
      dockerdWithinRunnerContainer: true
      env:
        - name: STARTUP_DELAY_IN_SECONDS
          value: "10"
---
apiVersion: actions.summerwind.dev/v1alpha1
kind: HorizontalRunnerAutoscaler
metadata:
  name: senteca-runner-autoscaler
spec:
  scaleTargetRef:
    name: senteca-runner
  scaleDownDelaySecondsAfterScaleOut: 60
  minReplicas: 0
  maxReplicas: 5
  scaleUpTriggers:
  - githubEvent:
      checkRun:
        types: ["created"]
        status: "queued"
    amount: 1
    duration: "5m"

This is how my GitHub webhook looks like:

Any hints as to what may be wrong on my end are welcome. Thanks in advance :^)