I think the code you uploaded is for M5Stack and not M5Core2.

Please use #include <M5Core2.h> at the top and remove M5.Power.begin() which is required for M5Stack only.

#include <M5Core2.h>

void setup() {
  M5.begin();
    
  M5.Lcd.print("Hello World");
}

void loop() {
}

You probably will need to download and install the proper library for M5Core2 as well.

Thanks
Felix

OS: Mac Big Sur

// the setup routine runs once when M5Stack starts up
void setup(){

  // Initialize the M5Stack object
  M5.begin();

  /*
    Power chip connected to gpio21, gpio22, I2C device
    Set battery charging voltage and current
    If used battery, please call this function in your project
  */
  M5.Power.begin();
    
  // LCD display
  M5.Lcd.print("Hello World");
}

// the loop routine runs over and over again forever
void loop() {

}



Result debug:

esptool.py v3.0-dev
Serial port /dev/cu.usbserial-0203EDF5
Connecting....
Chip is ESP32-D0WDQ6-V3 (revision 3)
Features: WiFi, BT, Dual Core, 240MHz, VRef calibration in efuse, Coding Scheme None
Crystal is 40MHz
MAC: 84:cc:a8:61:90:50
Uploading stub...
Running stub...
Stub running...
Changing baud rate to 921600
Changed.
Configuring flash size...
Auto-detected Flash size: 16MB
Compressed 8192 bytes to 47...
Writing at 0x0000e000... (100 %)
Wrote 8192 bytes (47 compressed) at 0x0000e000 in 0.0 seconds (effective 10848.4 kbit/s)...
Hash of data verified.
Flash params set to 0x024f
Compressed 17104 bytes to 11153...
Writing at 0x00001000... (100 %)
Wrote 17104 bytes (11153 compressed) at 0x00001000 in 0.2 seconds (effective 899.1 kbit/s)...
Hash of data verified.
Compressed 413360 bytes to 171576...
Writing at 0x00010000... (9 %)
Writing at 0x00014000... (18 %)
Writing at 0x00018000... (27 %)
Writing at 0x0001c000... (36 %)
Writing at 0x00020000... (45 %)
Writing at 0x00024000... (54 %)
Writing at 0x00028000... (63 %)
Writing at 0x0002c000... (72 %)
Writing at 0x00030000... (81 %)
Writing at 0x00034000... (90 %)
Writing at 0x00038000... (100 %)
Wrote 413360 bytes (171576 compressed) at 0x00010000 in 3.2 seconds (effective 1031.9 kbit/s)...
Hash of data verified.
Compressed 3072 bytes to 129...
Writing at 0x00008000... (100 %)
Wrote 3072 bytes (129 compressed) at 0x00008000 in 0.0 seconds (effective 3453.6 kbit/s)...
Hash of data verified.

Leaving...
Hard resetting via RTS pin...

did you post the same text twice by accident? Or was that a glitch in the forum software?

Anyhow, there is nothing wrong in GitHub examples regarding Serial.begin() - there is no need for a pull-request or fixing a software library or example.

Everything's ok. (Only the personal example of @HausBusDe he posted is incorrect.)

Nothing needs to be done.

Thanks
Felix

no, the code using Serial.begin() twice is not on GitHub - I think it is simply code @HausBusDe put together himself and posted in the forum here.

Thanks
Felix

@HausBusDe posted the code here. The issue seems to be Serial.begin() which when called twice (once in the code and once through M5.begin()) causes that issue.

Thanks
Felix