AddPrinterConnection with Win32_Printer fails

I have a simple programm that adds a specific printer connection to the server and prints on that printer a pdf document. After printing the document, the printer connection will be deleted.

Now everything works fine when I launch the app as my own admin-account. But when I launch the app with a service user-account, I can't add the printer connection. It fails with an error code 87: INVALID_PARAMETER

Note: If the printer connection on the machine (server) is available, then I can print with the service user-account. Only adding a printer connection, that does not exists, does not work.

Here is the code snippet:

    private static ManagementScope oManagementScope = null;

    public static bool AddPrinter(string printerName)
    {
        var result = false;
        try
        {
            oManagementScope = new ManagementScope(ManagementPath.DefaultPath);
            oManagementScope.Connect();

            using (ManagementClass win32Printer = new ManagementClass("Win32_Printer"))
            {
                using (ManagementBaseObject inputParam = win32Printer.GetMethodParameters("AddPrinterConnection"))
                {
                    inputParam.SetPropertyValue("Name", printerName);

                    using (ManagementBaseObject methodResult = win32Printer.InvokeMethod("AddPrinterConnection", inputParam, null))
                    {
                        uint errorCode = (uint)methodResult.Properties["returnValue"].Value;

                        switch (errorCode)
                        {
                            case 0:
                                Logger.LogInfo("Successfully connected printer.");
                                result = true;
                                break;
                            case 5:
                                Logger.LogError("Access Denied.");
                                break;
                            case 123:
                                Logger.LogError("The filename, directory name, or volume label syntax is incorrect.");
                                break;
                            case 1801:
                                Logger.LogError("Invalid Printer Name: " + printerName);
                                break;
                            case 1930:
                                Logger.LogError("Incompatible Printer Driver.");
                                break;
                            case 3019:
                                Logger.LogError("The specified printer driver was not found on the system and needs to be downloaded.");
                                break;
                            default:
                                Logger.LogError("Could not add the specific printer, Error Code: " + errorCode);
                                break;
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Logger.LogError(ex.Message + ", " + ex.InnerException?.Message);
        }

        return result;
    }

We already tried to add the same permissions on the service user, as I have on my admin-account. I still get the error code 87 while adding a printer connection.

As I have researched a bit about the error code 87, I found out that it means something like INVALID PARAMETER. But I can't figure out which parameter should be invalid, and why does it work on the server when I launch it with my admin-account?

Any help is welcome

Thanks