@felmue Super, now it works! Thanks, Hans

@felmue , I tried your proposal with Arduino IDE and my M5Stack Paper:

gpio_hold_en(M5EPD_MAIN_PWR_PIN);
gpio_deep_sleep_hold_en();

but get an error :

invalid conversion from 'int' to 'gpio_num_t' [-fpermissive]

Whats going wrong?

Hans