Megatinycore Serial.print outputting garbage

PlatformIO IDE
1

Hi I just started tinkering with the ATtiny 1-series on PlatformIO. I managed to create a blink program that worked flawlessly. However when I added the command to print to the serial port, it only outputted garbage. I know this isn’t an issue with my hardware or my code because I tried it in the ArduinoIDE and it worked normally.

Here is my code:

#include <Arduino.h>
#include <avr/io.h>

#define LED_AVR PIN3_bm

void setup() {
  PORTA.DIRSET = LED_AVR;
  Serial.begin(9600);
}

void loop() {
  PORTA.OUT |= LED_AVR;
  Serial.println("Led ON");
  delay(1000);
  PORTA.OUT &= ~LED_AVR;
  Serial.println("Led OFF");
  delay(1000);
}

And here is my platformio.ini file:

; PlatformIO Project Configuration File
;
;   Build options: build flags, source filter
;   Upload options: custom upload port, speed and extra flags
;   Library options: dependencies, extra library storages
;   Advanced options: extra scripting
;
; Please visit documentation for the other options and examples
; https://docs.platformio.org/page/projectconf.html

[env:ATtiny416]
platform = atmelmegaavr
board = ATtiny416
framework = arduino
upload_protocol = custom
upload_command = pyupdi -d tiny416 -b 19200 -c COM9 -f .pio\build\ATtiny416\firmware.hex -v

Thanks for the help