ZD410 bluetooth communication in Windows UWP


I am trying to send ZPL commands to my ZD410 over Bluetooth with a Raspberry Pi 3 running Windows 10 IoT.
To test connecting to it from my Windows 10 PC, I have successfully paired the printer to my PC. If I can get it running on my PC, I will pair it with my RPi3 and try to remote debug from Visual Studio.
I am trying to connect as specified here: printing - Windows IoT - Zebra Bluetooth Printer - Stack Overflow . I have tried scanning to find the device but the method returns an empty DeviceInformation collection. My code is below:
public sealed partial class MainPage : Page     {         public MainPage()         {             this.InitializeComponent();         }           private async void button_Click(object sender, RoutedEventArgs e)         {             var devices = await DeviceInformation.FindAllAsync(RfcommDeviceService.GetDeviceSelector(RfcommServiceId.SerialPort));               if (devices.Count() == 0)             {                 textBox.Text = "No devices found.";             }             else             {                 foreach (var device in devices)                 {                     listView.Items.Add(device.Name);                 }             }         }     } 
I have added the device capabilities to my manifest:
Any help would be appreciated.