GPRS/GSM A9G hardware reset via pin

Hello! I Recently bought a board mountain the A9G module from Ai-thinker. The module has a reset pin, which I would like to use to reset it. The documentation is poor and incomplete. After setting the pin to output mode, I write HIGH, which according to a site should reset it. However I am unable to send AT commands to the module after that, it looks stuck with two network and status LEDs on. Which is the correct procedure to reset it?

The module schematics I find show the reset button pulls the reset line low. I suspect the reset input is active low with an internal pull-up. To do a reset you're going to want to set a low signal for 250ms then high again.

Hi, I'm using this schematic:
Immagine 2022-01-16 152631
However if I set D6 to high and then low after waiting 250ms, it starts the procedure like INIT, waiting for SIM, as in the power on phase, but then it becomes stuck: it cannot answer to AT commands anymore. It the module faulty?