K8ssandra and Cassandra Troubleshooting Expert

I'm seeking an expert in K8ssandra and Apache Cassandra to troubleshoot issues arising from our recent upgrade of the k8ssandra-operator.

While the upgrade was successful, and both the operator and Cassandra pods are running with accessible data, we're facing some post-upgrade challenges.

Key areas needing attention:
- nodetool behavior is not as expected
- JMX connectivity issues

Ideal skills and experience:
- Strong experience with K8ssandra and Apache Cassandra
- Proven troubleshooting skills in Kubernetes environments
- Familiarity with nodetool and JMX

Your expertise will help us restore functionality and ensure smooth operations.