Importing Execution Results removing defects link when status is updated via REST API

Defects linked to the Tests in a Test Execution gets removed when we update the status via REST API.

Steps to reproduce:

1. Consider a test in a Test Execution.
2. Link a Defect to the Test of the corresponding Test Execution
3. Use Xray JSON results REST API to import Execution results and update the Test Status. API used:

   /api/v2/import/execution 

1. JSON used: 

   {
       "testExecutionKey": "<TE-KEY>",
       "tests": [
           {
               "status": "PASSED", //modify the status from pass to fail or vice versa or even if we keep the same status
               "testKey": "<Test-Key>"
           }
       ]
   } 

Expected Result: The status of the test in the test execution should change without removing the linked defect.

Actual Result: The status of the test in the test execution changes, but, the linked Defect is also removed.