As of Consul 1.14 Consul K8s 1.0 uses Consul Dataplane by default instead of client agents. Vault does not currently support Consul Dataplane.
Vault K8s customers using Consul Storage backend on Kubernetes and considering an upgrade to Consul K8s 1.0/Consul 1.14 must refer to the guidelines in the Vault 1.12.x upgrade guide to ensure that their Kubernetes deployment continues to work. You will need to enable the client agent config and update your Helm chart, if Helm is being used.
Consul upgrade guidance on this topic is available.
There is no impact to Vault K8s customers using Consul storage backend with Consul K8s 0.49/Consul 1.13.x and lower.
Additionally, refer to this Vault documentation where compatibility is mentioned: