Grafana Operator in OpenShift errors when connecting to Prometheus

Grafana OpenShift operator version 5.8.0, running in OpenShift 4.12.45
→ Grafana v9.5.17 (68b350c5e6896aa019656d6558d7d186895186be)

After installing the Grafana Operator and loading a dashboard, I get a “No data” response in the dashboard panels, and I see a strange error:

For context, I had already given grafana-a-sa the cluster-monitoring-view cluster role and created a Datasource and given it the token I made for grafana-a-sa.

Online instructions I am following:
Deploying Grafana on Openshift 4 | Red Hat Cloud Experts Documentation
Custom Grafana dashboards for Red Hat OpenShift Container Platform 4.x … | by Kamlesh Prajapati | Medium