Caused by duplicate prometheus-kubelet services in kube-system. There should only be one. Note that helm chart uninstall is not clearing out this service.
Describe pod state. Check if cni says it is running out of IPs.
Use the clear_cni.sh script to clear out the cni state. This will cause a restart of the cni pods and free up the IPs.
k8snetworkplumbingwg/multus-cni#710 (comment)
Multus can get OOMKilled.
Increase resources for multus pods.
Prometheus can get OOMKilled if it is collecting too many series.
Reduce high-cardinality metrics or increase resources for prometheus pods.