Failed to make webhook authorizer

[sndtechnologyuk]

Installed istio-hpa onto kubernetes 1.22.6.
kube-metrics-adapter has the following in the logs.
I0512 15:53:23.575559 1 serving.go:273] Generated self-signed cert (apiserver.local.config/certificates/apiserver.crt, apiserver.local.config/certificates/apiserver.key) I0512 15:53:23.901168 1 serve.go:96] Serving securely on [::]:443 time="2022-05-12T15:53:23Z" level=info msg="Looking for HPAs" provider=hpa time="2022-05-12T15:53:23Z" level=info msg="Found 3 new/updated HPA(s)" provider=hpa I0512 15:53:24.147708 1 logs.go:49] http: TLS handshake error from 100.107.114.128:50213: remote error: tls: bad certificate E0512 15:53:24.148062 1 webhook.go:192] Failed to make webhook authorizer request: the server could not find the requested resource
Cluster has cert-manager installed if that makes any difference.