ElasticSearch(7.10.3): Opendistro(1.13.2) SQL: Query failing at random times

Question

When executing sql query via opendistro llike:

POST /_opendistro/_sql?format=jdbc { "query":"show tables like my_index_prefix%" }

This executes successfully at certain time and fails at random intervals? What might be the issue?

On failure, it gives the below error:

{
  "error" : {
    "root_cause" : [
      {
        "type" : "invalid_index_name_exception",
        "reason" : "Invalid index name [_opendistro], must not start with '_', '-', or '+'",
        "index_uuid" : "_na_",
        "index" : "_opendistro"
      }
    ],
    "type" : "invalid_index_name_exception",
    "reason" : "Invalid index name [_opendistro], must not start with '_', '-', or '+'",
    "index_uuid" : "_na_",
    "index" : "_opendistro"
  },
  "status" : 400
}