Following XPATH query against CPS Core works fine:
 
curl --location --request GET 'http://localhost:8883/cps/api/v1/dataspaces/E2EDemo/anchors/coverage-area-onap/nodes/query?cps-path=/ran-coverage-area&include-descendants=true' \
--header 'Authorization: Basic Y3BzdXNlcjpjcHNyMGNrcyE=' \
--header 'Cookie: JSESSIONID=node0k5ub7r3ezt8ginq7xu65shcf25.node0' \
--data-raw ''
Template is created using:

curl --location --request POST 'http://localhost:8080/templates' --header 'Content-Type: application/json' --data-raw '{"templateId": "get-parentNode-list", "model": "ran-coverage-area", "requestType": "get", "xpathTemplate": "/ran-coverage-area", "includeDescendants": true}'

The following POST /execute/{model}/{template-id} is executed:

curl --location --request POST 'http://localhost:8080/execute/ran-coverage-area/get-parentNode-list' --header 'Authorization: Basic Y3BzdXNlcjpjcHNyMGNrcyE=' --header 'Cookie: JSESSIONID=node0k5ub7r3ezt8ginq7xu65shcf25.node0' --data-raw '{ "inputParameters": {}}'

There is no response from the API.