Tried some examples, with no success (black screen).

Uploaded successfully first program:
#include <M5stack.h>

void setup() {
M5.begin(true, false, true); // Cause no SD card inside
M5.Lcd.print("Hello Vince");
}

void loop() {
M5.update();
}

Then tried this program:
#include <M5stack.h>

void setup() {
M5.begin(true, false, true); // Cause no SD card inside
M5.Lcd.fillScreen(WHITE);
M5.Lcd.setCursor(100, 100);
M5.Lcd.setTextColor(RED);
M5.Lcd.setTextSize(5);
M5.Lcd.print("Hello Vince");
}

void loop() {
M5.update();
}

Unfortunatly, the second program always displays same as the first program (white text on black screen)
My programming method is simple: click the "PlatformIO: upload" button, wait for percentage progress, and look at the screen.

Am I missing something ?

Second question: with this M5Stack-Black, do I need to call M5.Power.begin() after M5.begin(), and what are the consequences if I do not ?

Thanks for your responses