If the CycleCloud server and the cluster is in the same VNET, check the network security groups for the subnets in the VNET. Cluster nodes need to be able to reach the CycleCloud server at TCP 9443 and 5672. In the other direction, Azure CycleCloud needs to be able to reach ganglia (TCP 8652) and SSH (TCP 22) ports of the cluster for system and job monitoring.
You may need to add a public IP address.
If the error message indicates a return proxy, check the return proxy settings.
After updating network or proxy settings, you can test connectivity by SSHing into the node as the cyclecloud user and using curl -k {https://error-message-url}.
After validating that network connectivity is fixed, you will need to terminate and restart the node.
Source: Azure Documentation