Error connecting with paired device in iOS

[EreborKing]

When trying to connect with a paired device on iOS, always throws exception.

With the async method, throws the follwing exception:
await client.ConnectAsync(device.DeviceAddress, BluetoothService.SerialPort);
"Could not initialize an instance of the type 'ExternalAccessory.EASession': the native 'initWithAccessory:forProtocol:' method returned nil.\nIt is possible to ignore this condition by setting ObjCRuntime.Class.ThrowOnInitFailure to false."`

With the sync method, throws the follwing exception:
BluetoothEndPoint bluetoothEnd = new BluetoothEndPoint(device.DeviceAddress, BluetoothService.DirectPrinting);
client.Connect(bluetoothEnd)
System.NullReferenceException: Object reference not set to an instance of an object.

I'm trying to connect with a Bluetooth printer.

[peterfoot]

What kind of printer is it? Is it Apple MFI compatible and is it in the correct mode? (some printers you have to switch between serial port and apple modes)

[EreborKing]

I'm currently testing with the Woosim Printer model WSP-R350. It is in the correct mode (Bluetooth IAP mode), however i'm not sure if it is MFI Compatible.
I can list the device using the plugin, attempt a connection to it, but it throws that exception.