Get-Certificate cmdlet do not transmit credentials for authentication

Hello,

I'm trying to use Get-Certificate cmdlet which supports -credential parameter. Whenever I use that parameter though I can not see credential being passed to remote machine, request comes as anonymous. Below is header capture on remote machine when I use Get-Certificate with -cred parameter specified. It supposed to have "Authorization" header and but it's not passing it.

On the other hand if I omit -cred parameter and try to access with currrent account I do see request coming in with "Authorization" header.

What am I missing here?

GENERAL_REQUEST_HEADERSHeaders="Cache-Control: no-cache
Connection: Keep-Alive
Pragma: no-cache
Content-Length: 1270
Content-Type: application/soap+xml; charset=utf-8
Host: sjvappcaissue1.corp.nai.org
User-Agent: MS-WebServices/1.0"