SqlServerSecureConnection: Certificate Thumbprint is case-sensitive

[Teutenberg]

Details of the scenario you tried and the problem that is occurring

DSC resource works and configures certificate but it won't show in Configuration manager if the certificate thumbprint is upper case.

PowerShell command returns thumbprint upper-case:
(Get-ChildItem cert:\LocalMachine\my | ? FriendlyName -eq "SQL Certificate" | Select-Object -Property Thumbprint).Thumbprint

Suggested solution to the issue

Either document that lower case is required, or force thumbprint lower

The DSC configuration that is used to reproduce the issue (as detailed as possible)

[string]$CertificateThumbprint = (Get-ChildItem cert:\LocalMachine\my | ? FriendlyName -eq "SQL Certificate" | Select-Object -Property Thumbprint).Thumbprint
$SqlServices = Get-DbaService -Type Engine | Where { $_.State -ieq "Running" }

foreach ($srv in $SqlServices) {
    if ($srv.StartName -ieq "LocalSystem") {
        $ServiceAccount = "NT AUTHORITY\SYSTEM"
    }
    else {
        $ServiceAccount = $srv.StartName
    }

    $Params = @{
        InstanceName    = $srv.InstanceName
        Thumbprint      = $CertificateThumbprint
        ForceEncryption = $false
        Ensure          = 'Present'
        ServiceAccount  = $ServiceAccount
    }
    
    if (Invoke-DscResource -ModuleName SqlServerDsc -Name SqlServerSecureConnection -Property $Params -Method Test) {
        Write-Host "Skipping SqlServerSecureConnection... Instance already configured: $($srv.InstanceName)"
    }
    else {
        Write-Host "Configuring SqlServerSecureConnection... Instance: $($srv.InstanceName)"
        Invoke-DscResource -ModuleName SqlServerDsc -Name SqlServerSecureConnection -Property $Params -Method Set -Verbose
    }
}