Hi @EnterpriseArchitect ,
Per my test, we will get a windows to log in like following picture after call the cmdlet, and your browser doesn't support this function.
This error means you need to update your browser or download Edge as default browser. As a workaround, you can also use following cmdlet without log with a window. We can write the user account and secret into the cmdlet. Please make a reference
$username = "admin@contoso.sharepoint.com"
$password = "password"
$cred = New-Object -TypeName System.Management.Automation.PSCredential -argumentlist $userName, $(convertto-securestring $Password -asplaintext -force)
Connect-SPOService -Url https://contoso-admin.sharepoint.com -Credential $cred
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