@oscillator
The CORE2 API is different from the CORE API. Different hardware.

Here is my INIT code in Arduino:
M5.begin();
M5.Lcd.print("IOT DEVICE MONITOR");
WiFi.begin(ssid, pass); //connect to WiFi
delay(2000);
Serial.begin(115200);
Serial.println("IOT DEVICE MONITOR");

The response is:
M5Core2 initializing...axp: vbus limit off
axp: gpio1 init
axp: gpio2 init
axp: rtc battery charging enabled
axp: esp32 power voltage was set to 3.35v
axp: lcd backlight voltage was set to 2.80v
axp: lcd logic and sdcard voltage preset to 3.3v
axp: vibrator voltage preset to 2v
touch: FT6336 ready (fw id 0x10 rel 1, lib 0x300E)
OK

The first M5.Lcd.print is displayed, then we go no further, stopping at the "OK" message after FT6336.
About one in 10x it works correctly. What is missing here?