Host URL Policy for Custom Connector - Internal Server Error in Power Automate Flow

I created a custom connector with policy 'set host URL'

but when I tried to test it, getting below error - 

{
  "error": {
    "code": 500,
    "message": "An attempt was made to access a socket in a way forbidden by its access permissions 10.241.51.188:80",
    "source": "unitedstates-002.azure-apim.net",
    "path": "forward-request",
    "policyId": "",
    "clientRequestId": "17d708b0-b16c-4aa6-8afd-35901f0f25dc"
  }
}

When I tried to use this custom connector in power automate flow getting 'internal server error'.

Please let me know if you can help.