duplicate doc of uniqueKey

[Novin Novin]

Hi Guys,

I end up with duplicate docs in solr cloud. I don't know how to debug it.
So looking for help here please.

Below is details:
Solr 6.6.2
zookeeper 3.4.10

Below is example of duplicate record of Json:

{
  "responseHeader":{
    "zkConnected":true,
    "status":0,
    "QTime":0,
    "params":{
      "q":"*:*",
      "distrib":"false",
      "indent":"on",
      "fl":"id",
      "fq":"id:mid531281",
      "wt":"json"}},
  "response":{"numFound":2,"start":0,"docs":[
      {
        "id":"mid531281"},
      {
        "id":"mid531281"}]
  }}

schema file contains:
<field name="id" type="string" indexed="true" stored="true" required="true"
multiValued="false" docValues="true"/>

<uniqueKey>id</uniqueKey>

Let me know if extra information required. Any help would be really
appreciated.

Regards,
Novin