As per the doc
https://docs.percona.com/percona-operator-for-mysql/pxc/users.html
Its indicated that "clustercheck" is used for liveness and readiness probe.
User "monitor" is used now.
https://github.com/percona/percona-xtradb-cluster-operator/blob/main/build/liveness-check.sh
Please fix this and also provide the context on users being used and the purpose, for example monitor user is used by liveness check and also pmm client etc

CC