When deploying the chart with default values you see an error like this:
Helm upgrade failed: failed to create resource: FlinkCluster.flinkoperator.k8s.io "flink-flink-cluster-flink-job-cluster" is invalid: spec.job.parallelism: Invalid value: "null": spec.job.parallelism in body must be of type integer: "null"
When deploying the chart with default values you see an error like this:
Fixing the typo here resolves the issue.