Incorrect Meta data when Query node not also an Index node

cpq run on client machine 172.23.100.28.
cbq -engine=http://172.23.100.21:8093
cbq> select * from system:indexes;
{
"requestID": "9e7aa7bf-70d4-4faa-ac19-dada5c63b7ec",
"signature":

,
"results": [
],
"errors": [
{
"code": 11000,
"msg": "System datastore error - cause: Failed to load indexes for keyspace bucket-1 - cause: HTTP error 400 Bad Request getting \"http://127.0.0.1:8091/pools/default/buckets/bucket-1/ddocs\":

"
}
],
"status": "errors",
"metrics":

}

you will see that it reports a system error failiing to access meta data on 127.0.0.1:8091. the metadata is on 172.23.100.17-20.
if i stop this automatically started cpq-engine (created by adding a node with service Query only thru console)
and restart it with cbq-engine -datastore=http://172.23.100.17, the above issue retrieving system:indexes went away.