I am getting this error while using helm 3 only. In helm 2 it's working as expected.Here is the secret object's manifest secret.yaml

apiVersion: v1
data:
  couchbase_password: {{ .Values.secrets.cbPass | quote }} 
kind: Secret
metadata:
  name: {{ include "persistence.name" .}}-cb-pass
type: Opaque

---

apiVersion: v1
data:
  couchbase.crt: {{ .Values.secrets.encodedCouchbaseCrt | quote }} 
kind: Secret
metadata:
  name: {{ include "persistence.name" .}}-cb-crt
type: Opaque

And here are some contents of the values.yamlfile

configmap:
  #support for oxtrust API
  gluuOxtrustApiEnabled: false
  gluuOxtrustApiTestMode: false
  gluuCasaEnabled: true

secrets: 
  cbPass: UEBzc3cwcmQK # UEBzc3cwcmQK
  encodedCouchbaseCrt: LS0tLS1CRUdJTiBDR

When I do helm template test . I get

---
# Source: gluu-server-helm/charts/persistence/templates/secrets.yaml
apiVersion: v1
data:
  couchbase.crt: "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" 
kind: Secret
metadata:
  name: persistence-cb-crt
type: Opaque
---
# Source: gluu-server-helm/charts/persistence/templates/secrets.yaml
apiVersion: v1
data:
  couchbase_password:  "UEBzc3cwcmQK" 
kind: Secret
metadata:
  name: persistence-cb-pass
type: Opaque

When I use default data directly without referencing values file, it still doesn't work.

Helm version version.BuildInfo{Version:"v3.0.2", GitCommit:"19e47ee3283ae98139d98460de796c1be1e3975f", GitTreeState:"clean", GoVersion:"go1.13.5"}

kubectl version

Client Version: v1.16.3
Server Version: v1.17.0