Steps to reproduce:

1. Have a discovery rule

1. Create a item prototype, like this:
2. This item prototype have Preprocessing step like this :
   1. In fact, have also test with theses paths, without success
      1. $.[?(@.vmdisplayname == "HIDDENINFO")].state
      2. $.[?(@.vmdisplayname=="HIDDENINFO")].state
      3. $..[?(@.vmdisplayname == "HIDDENINFO")].state
      4. $..[?(@.vmdisplayname =~ "HIDDENINFO")].state
3. Test with item preprocessing tester and theses values below, ALL work correctly and return good result.

1. 1. [
      {
      "jobsessionuid": "urn:veeam:BackupJobSession:5d7bb890-4d97-44c1-a4cc-42dc6c24071f",
      "creationtimeutc": "2019-08-22T20:08:57Z",
      "endtimeutc": "2019-08-22T20:11:41Z",
      "state": "Completed",
      "result": "Success",
      "reason": "",
      "totalsize": 1073741824000,
      "vmuid": "urn:VMware:Vm:dcb66bd9-a188-47f1-8742-d2f5737e02ac.vm-99",
      "vmdisplayname": "HIDDENINFO",
      "name": "HIDDENINFO@2019-08-22 20:08:57",
      "uid": "urn:veeam:BackupTaskSession:30335919-136f-4743-a5d9-100013a11c4f",
      "href": "https://veeam:9398/api/backupTaskSessions/30335919-136f-4743-a5d9-100013a11c4f?format=Entity",
      "type": "BackupTaskSession"
      },
      {
      "jobsessionuid": "urn:veeam:BackupJobSession:5d7bb890-4d97-44c1-a4cc-42dc6c24071f",
      "creationtimeutc": "2019-08-22T20:08:57Z",
      "endtimeutc": "2019-08-22T20:11:41Z",
      "state": "Completed",
      "result": "Success",
      "reason": "",
      "totalsize": 1073741824000,
      "vmuid": "urn:VMware:Vm:dcb66bd9-a188-47f1-8742-d2f5737e02ac.vm-99",
      "vmdisplayname": "HIDDENINFO2",
      "name": "HIDDENINFO@2019-08-22 20:08:57",
      "uid": "urn:veeam:BackupTaskSession:30335919-136f-4743-a5d9-100013a11c4f",
      "href": "https://veeam:9398/api/backupTaskSessions/30335919-136f-4743-a5d9-100013a11c4f?format=Entity",
      "type": "BackupTaskSession"
      }
      ]

Result:
In "production" mode, with the SAME JSON array value, that fail :
Expected:
Same result of Test preprocessing :

Best regards,