Invoke-RestMethod : The underlying connection was closed: An unexpected error occurred on a receive

Hi everyone,

To Introduce myself : Working as a Power BI Developer with PBI Admin access. 

My Powershell script stoped working suddenly and prompting me an error saying the underlying connection was closed. This was all working fine few days back.

Here is a part of my script that calls REST API to export the reprot in pdf format. 

Login-PowerBI

$groupid = "Hidden"
$Reportid = "Hidden"
$Folder = "c:\temp\"
$Body = "{`”format`”:`”pdf`”}"
$filename = $Folder + "PowerBIMetrics.pdf"

$StatusCheck=0

# Get token
$token = Get-PowerBIAccessToken -AsString
##write-host $token

# Building Rest API header with authorization token
$authHeader = @{
"Authorization"= $token
"Content-Type" = "application/json"
}

$url1 = "https://api.powerbi.com/v1.0/myorg/groups/$groupid/reports/$Reportid/ExportTo"

Invoke-RestMethod -Method Post -uri $url1 -Headers $authHeader -body $Body

I have tried to look for solution and many of them (Power BI community/ DBA) is saying I need to add extra line  of code below before I execute the Invoke-ResMethod command line,

[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12

Unfortunately, I'm getting same error message.

I also tried to used otther method from link below but no luck either.
PowerShell - The underlying connection was closed: An unexpected error occurred on a send. - darrenjrobinson - Bespoke Identity and Access Management Solutions

Thank you.

Eric