Description of problem:
TemplateInstance object in OCP 3.11 is not taking values defined in secret passed in spec.secret.name and therefore the objects defined in the template are not getting instantiated

Version-Release number of selected component (if applicable):
OCP 3.11

How reproducible:
Always

Steps to Reproduce:
1. oc new-project mycloudpoc
2. Create service account:

  $ oc create sa mycloudadmin
  $ oc adm policy add-cluster-role-to-user cluster-admin system:serviceaccount:openshift-infra:template-instance-controller 
  $ oc adm policy add-cluster-role-to-user cluster-admin system:serviceaccount:openshift-infra:resourcequota-controller 
  $ oc create clusterrolebinding mycloudamdin --clusterrole cluster-admin --serviceaccount=mycloudpoc:mycloudadmin

3. Create template file: 

  $ oc create -f template.json

4. Create a secret "secrettest":

  curl -k \
    -X POST \
    -d @- \
    -H "Authorization: Bearer $TOKEN" \
    -H 'Accept: application/json' \
    -H 'Content-Type: application/json' \
    https://openshift.xxx.redhat.com:443/api/v1/namespaces/mycloudpoc/secrets <<EOF

{
  "kind": "Secret",
  "apiVersion": "v1",
  "metadata": {
    "name": "secrettest"
  },
  "stringData": {
      [...]
      "MEM": "4Gi",
      "PROJECT_ADMIN_USER": "foo-admin",
      "PROJECT_NAME": "openshift-proj011",
      "REQUESTER": "foo",
      "RITM": "xyz",
      [...]
  }
}
EOF

5. Instantiate previous created template directly through an API call like this:

curl -k \
    -X POST \
    -d @- \
    -H "Authorization: Bearer $TOKEN" \
    -H 'Accept: application/json' \
    -H 'Content-Type: application/json' \
    https://openshift.xxx.redhat.com:443/apis/template.openshift.io/v1/namespaces/mycloudpoc/templateinstances <<EOF
{
  "kind": "TemplateInstance",
  "apiVersion": "template.openshift.io/v1",
  "metadata": {
    "name": "secrettest"
  },
  "spec": {
    "secret": {
      "name": "secrettest"
    },
    "template": $(curl -k \
                    -H "Authorization: Bearer $TOKEN" \
                    -H 'Accept: application/json' \
                     https://openshift.xxx.redhat.com:443/apis/template.openshift.io/v1/namespaces/mycloudpoc/templates/odenprojcreation)
  }
}
EOF


Actual results:

Objects defined into the template are not created.

Expected results:

Objects should be created.

Additional info:
Same procedure with OCP 3.7 works without issue.