BluetoothSerial blocks Serial I/O

[bob755]

Hello,

I'm using an ESP32 DEVKIT V1 and I've just installed the BluetoothSerial library which works fine.
However, after the program has executed the SerialBT.begin, there is a beep from the pc as if the USB has been unplugged and no more messages a received on the console.
In the following code snippet example, MESSAGE_1 is written to the console but not MESSAGE-2. If the line: SerialBT.begin("MYBTID"); is commented out, both messages appear.

BluetoothSerial SerialBT;

void setup() {
Serial.begin(115200);
delay(1000);
Serial.println("MESSAGE_1");
SerialBT.begin("MYBTID");
Serial.println("MESSAGE_2");
:
:
:

Can anyone help?

Thanks in advance.