sh.enableAutoSplit() returns Documentations failed validation

Hi,

I’m trying to enable the autosplit and get this back from the mongos. I have googled as much as I can cannot find anyone having this issue so I turn to this forum if anyone has had this issue and am I just missing something simple here?

> sh.enableAutoSplit()
Uncaught:
MongoServerError: Document failed validation
Additional information: {
  failingDocumentId: 'autosplit',
  details: {
    operatorName: '$jsonSchema',
    schemaRulesNotSatisfied: [
      {
        operatorName: 'oneOf',
        schemasNotSatisfied: [
          {
            index: 0,
            details: [
              {
                operatorName: 'properties',
                propertiesNotSatisfied: [
                  {
                    propertyName: '_id',
                    details: [
                      {
                        operatorName: 'enum',
                        specifiedAs: { enum: [ 'chunksize' ] },
                        reason: 'value was not found in enum',
                        consideredValue: 'autosplit'
                      }
                    ]
                  }
                ]
              },
              {
                operatorName: 'additionalProperties',
                specifiedAs: { additionalProperties: false },
                additionalProperties: [ 'enabled' ]
              }
            ]
          },
          {
            index: 1,
            details: [
              {
                operatorName: 'properties',
                propertiesNotSatisfied: [
                  {
                    propertyName: '_id',
                    details: [
                      {
                        operatorName: 'enum',
                        specifiedAs: {
                          enum: [
                            'balancer',
                            'automerge',
                            'ReadWriteConcernDefaults',
                            'audit'
                          ]
                        },
                        reason: 'value was not found in enum',
                        consideredValue: 'autosplit'
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
}