Sending data over serial port

Another odd thing that I am stuck on. my sketch uses the Serial command library which allows me to send a command to the arduino, over the serial port, to execute a function. this all works perfect when using the serial monitor in the Arduino IDE. In platform IO the serial monitor correctly displays messages printed to the Arduino serial port. when I send a command over serial , nothing seems to happen e.g. I send showVersion, which when using Arduino IDE will print the version of the sketch to the serial port. when using platform IO I see no response after sending the command.