Issue solved! It was only my load (the PIC18) which didn't take changes about this pin and grounded the pin.

Here my schematic.
I'm using GPIO3 to send a BLE State to my PIC18 to control the LED.
But after configure the GPIO3 as an OUTPUT on Arduino IDE, nothing came out.
If I'm using same code in Arduino but change GPIO3 by GPIO6 it is working perfectly as it should !

As I said, it worked fine on ...

Yes absolutly. You need to connect GPIO8 to Vcc through 10k resistor to enable boot mode.

Hi,
I'm here again regarding my board.
I've done a v2. Based on v1 hand modified.
But now I can't drive GPIO3. It was previously working.

I checked, I have the same ESP32-C3 module as before : M4N4.
I also have the same code.
I checked the datasheet again, and GPIO3 doesn't seem to be reserved for ...

THANK YOU very much !
You are right !
I've looked about 50 times in the datasheet and the tab about Pin Configuration for Download Boot and didn't remember the GPIO8!
You give me the right question to clarify my view ! Too much time on it to still get a global view !

Hi,
I can't post it entirely.
I reached here for help because I sent an email to Espressif for help and never got an answer.
So I attached the interesting part for my topic, and hid some names.
Thanks for your time to help.

Hi everyone,
I designed a board with an ESP32-C3-MINI-1U, and ordered it from JLCPCB (manufacture and assembly).

I copied the schematic of the ESP32-C3-DevKitM-1 for the programming circuit via UART only, through USB (with USB converter).
I had to use this method because I'm using another µC on the ...