I was trying to administer our tenant’s Microsoft Teams accounts, but the connection timed out constantly on my home comp. I assumed it’s because my Office installation’s messed up due to constant switching between 2016 and 2019 Preview.

For the googlers:

Get-CsPowerShellEndpoint : The operation has timed out
At C:\Program Files\Common Files\Skype for Business Online\Modules\SkypeOnlineConnector\SkypeOnlineConnectorStartup.psm1:108 char:26
+ ...      $targetUri = Get-CsPowerShellEndpoint -TargetDomain $adminDomain
+                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (:) [Get-CsPowerShellEndpoint], WebException
    + FullyQualifiedErrorId : System.Net.WebException,Microsoft.Rtc.Management.OnlineConnector.GetPowerShellEndpointCmdlet

Then I switched over to my laptop. Guess what, same thing. This is where I started to suspect it has something to do with me enabling IPv6 for my home connection recently.

So I disabled IPv6 for my Ethernet adapter, aaand guess what? PowerShell session works immediately.

Microsoft, go home, you’re drunk.