Okay.
This board comes with 2 USB ports.
The one below the RGB LED is the native USB.
The other one is UART.
Your board .json defines USB_MODE=1 and USB_CDC_ON_BOOT=1
This means Serial object is routed to the native USB (HWCDC).
See ESP32-S3 native USB interface and Serial Monitor missing first messages - #10 by sivar2311
That might be the reason you don’t see anything on the serial monitor.
If you use the UART USB connector, your code must use Serial0.
Take a look beside the RGB LED.
There is a soldering bridge you might need to close to get the on board RGB-LED to work.