Elasticsearch Operator shows failed to get index settings - failed to decode response body

Issue

• Elasticsearch Operator pod logs show error messages:

2021-12-14T21:37:18.230126853Z {"_ts":"2021-12-14T21:37:18.230031522Z","_level":"0","_component":"elasticsearch-operator","_message":"failed to get index settings","_error":{"cause":{"Value":"string","Type":{},"Offset":66,"Struct":"IndexingSettings","Field":"settings.index.format"},"destination_type":"estypes.IndexSettings","index":".kibana-6","msg":"failed to decode response body"},"cluster":"elasticsearch","index":".kibana-6","namespace":"openshift-logging"}
2021-12-14T21:37:18.749716795Z {"_ts":"2021-12-14T21:37:18.749586586Z","_level":"0","_component":"elasticsearch-operator","_message":"failed to get index settings","_error":{"cause":{"Value":"string","Type":{},"Offset":75,"Struct":"IndexBlocksSettings","Field":"settings.index.blocks.write"},"destination_type":"estypes.IndexSettings","index":".kibana_1","msg":"failed to decode response body"},"cluster":"elasticsearch","index":".kibana_1","namespace":"openshift-logging"}

• Indices exist in Elasticsearch, but nothing appears in Kibana