Windows Server 2016上Invoke-WebRequest发送永久错误排查求助

我在Windows Server 2016系统上使用PowerShell v5.1编写脚本，通过公司专用代理监控CrowdStrike云端点https://ts01-b.cloudsink.net的可用性，脚本代码如下：

$URLAddress = "https://ts01-b.cloudsink.net"
$ProxyAddress = "http://proxyout.dev:8080"

$response = $null
$errorcode = $null

[Net.ServicePointManager]::SecurityProtocol = "tls12, tls11, tls"


try
{
$request = Invoke-WebRequest -Uri $URLAddress -Method Get -UseBasicParsing -DisableKeepAlive -MaximumRedirection 0 -Proxy $ProxyAddress -ProxyUseDefaultCredentials

$response = $request.StatusCode
Write-Host "Status Code -- $response"
}
catch
{
$errormessage = $_.Exception.Message
$errorcode = $_.Exception.Response.StatusCode.Value__
}


IF ($response -eq '200')
{
IF ($errorcode -eq $null)
{
  Write-Host "url: ""$URLAddress"" is avalible. `nStatus Code: $response"

}
ELSE
{
  Write-Host "url: ""$URLAddress"" is avalible but porxy: ""$proxydev"" has an error, `nError Code: $errorcode `nError Message:`n$errormessage. `nStatus Code: $response"
}
}
ELSE
{
  Write-Host "url: ""$URLAddress"" is not avalible. `nStatus Code: $response `nError Code: $errorcode `nError Message:`n$errormessage"
}

$request.BaseResponse.Close() 

脚本运行时持续出现错误：

The underlying connection was closed: An unexpected error occurred on a send.

奇怪的是，在目标服务器本地运行该脚本却完全正常。

通过SSL报告分析确认，ts01-b.cloudsink.net使用TLS 1.2版本，因此无需绕过SSL证书校验（如[System.Net.ServicePointManager]::ServerCertificateValidationCallback = {$true}这类常见方案）。

需要说明的是，出现问题的服务器供公司其他开发者频繁使用，他们常手动或通过微软SCOM监控代理运行PowerShell脚本。我无法确定问题根源，想问有没有人遇到过类似问题？

内容的提问来源于stack exchange，提问作者edwio