Invalid characters Arduino, Bluetooth (HM10 ) and Xamarin.Forms - xamarin

Question

I am having an issue trying to send commands to my Arduino Mega from my Android Xamarin.Forms app. When i use Bluetooth terminal app from play store it works, but my code does not. In the Arduino terminal i am just getting squares as if it is a baud rate issue or something. but from what i can see the baud rate is always determined by the device, which defaults to 9600 for the HM10.
I am using this library for the bluetooth https://github.com/xabre/xamarin-bluetooth-le
Arduino Sketch (works with bt terminal app)
void loop()
{
// Read from the Bluetooth module and send to the Arduino Serial Monitor
if (Serial3.available())
{
byte y = Serial3.read();
//int x = (int)y;
Serial.write(y);
}
// Read from the Serial Monitor and send to the Bluetooth module
if (Serial.available())
{
c = Serial.read();
// do not send line end characters to the HM-10
if (c != 10 & c != 13)
{
Serial3.write(c);
}
// Echo the user input to the main window.
// If there is a new line print the ">" character.
if (NL) { Serial.print("\r\n>"); NL = false; }
Serial.write(c);
if (c == 10) { NL = true; }
}
}
Then my send code in my Xamarin.Forms app
private async Task Button_ClickedAsync(object sender, EventArgs e)
{
if (_charataristice != null && _charataristice.CanWrite)
{
var data = Convert.ToByte(16);
_charataristice.WriteType = CharacteristicWriteType.WithoutResponse;
await _charataristice.WriteAsync(new[] { data });
}
}
Would appreciate any help, the value i am trying to revive is alwasy a number and should fall within one byte.