It nets down to that the M5Dials are not responding anymore, I can upload a basic "Hello World" sketch, but even the USBSerial.print("hello world\n");
isn't displayed on the terminal. A more 'advanced' sketch with

void setup()
{
  USBSerial.begin(115200);
  delay(5000);

  USBSerial.printf("Starting...\n\n");
  auto cfg = M5.config();
  M5Dial.begin(cfg, true, false);
  M5Dial.Display.setTextSize(1);
  M5Dial.Display.drawString("testing", 25, 75);
}

isn't showing on the Dial neither.
I've tried all the usual suspects, changing ports, cables, baudrates, but I don't get any response out of the two devices.
I'm using the PlatformIO setup and my platform.ini file looks like:

[env:m5stack-stamps3]
platform = espressif32
board = m5stack-stamps3
framework = arduino
lib_deps = 
	m5stack/M5Unified@^0.1.16
	mbed-kazushi2008/HTTPClient@0.0.0+sha.cf5d7427a9ec
	bblanchon/ArduinoJson@^7.1.0
	gilmaimon/ArduinoWebsockets@^0.5.4
	bodmer/TFT_eSPI@^2.5.43
	m5stack/M5Dial@^1.0.2
upload_speed = 115200
monitor_speed = 115200
board_upload.erase_flash = true

Is there any way I can restore the factory settings or do anything to get them back in working order?

Many thanks!