resource.not.found Error while trying to check the Report Execution Status REST_V2 api

Hi There!.

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><errorDescriptor><errorCode>resource.not.found</errorCode><message>Resource b5cd4deb-fe50-4890-a7be-812f541826ea not found.</message><parameters><parameter>b5cd4deb-fe50-4890-a7be-812f541826ea</parameter></parameters></errorDescriptor>

I am getting above mentioned errror,when I am trying to get the Reeport Execution Status using REST API V2. Whereas I get response of Report Execution Status when submitted for Execution as "Ready" along with Request ID and Export ID.

Detailed Steps - 

POST:
https://<domain>/reportservice/rest_v2/reportExecutions

Param:
<reportExecutionRequest>
    <reportUnitUri>/Custom_Reports/Reports/P_Report</reportUnitUri>
    <async>false</async>
    <freshData>false</freshData>
    <saveDataSnapshot>false</saveDataSnapshot>
    <outputFormat>pdf</outputFormat>
    <interactive>true</interactive>
    <ignorePagination>true</ignorePagination>
    <pages>1</pages>    
</reportExecutionRequest>

Response

<reportExecution> <exports> <export> <id>1711104f-bb2f-4659-bcc3-6a85d5b7bf6c</id> <outputResource> <contentType>application/xlsx</contentType> <fileName>Project_Name_Report.xlsx</fileName> <outputFinal>true</outputFinal> <pages>1</pages> </outputResource> <status>ready</status> </export> </exports> <reportURI>/Custom_Reports/Reports/Project_Name_Report</reportURI> <requestId>b5cd4deb-fe50-4890-a7be-812f541826ea</requestId> <status>ready</status> <totalPages>1</totalPages> </reportExecution>

Step 2 - Tying to check the status of RequestID

GET https://<domain>/reportservice/rest_v2/reportExecutions/b5cd4deb-fe50-4890-a7be-812f541826ea/status

Response:

<errorDescriptor> <errorCode>resource.not.found</errorCode> <message>Resource b5cd4deb-fe50-4890-a7be-812f541826ea not found.</message> <parameters> <parameter>b5cd4deb-fe50-4890-a7be-812f541826ea</parameter> </parameters> </errorDescriptor>

I am using JAVA to work on. I maintained the JSESSIONID, Domain, Path from Step -1 to Step -2 but still the same issue. 

I found these steps executing well in Postman. Please help me out on this, if I'm missing something,.. Any help is greatly appreciated. Thanks in advance!