I flashed my M5stack PoESP32 through the Arduino IDE to connect to a MQTT broker using this example: https://github.com/m5stack/M5Unit-PoESP32/blob/master/examples/Unit_PoESP32_M5Atom/MQTT_CLIENT/MQTT_CLIENT.ino

Now I'm trying to get the firmware back to it's shipped state and can not get it to work.
I've followed the instruction given on https://docs.espressif.com/projects/esp-at/en/latest/esp32/Get_Started/Downloading_guide.html and managed to flash the latest ESP32 WROOM firmware (https://dl.espressif.com/esp-at/firmwares/esp32/ESP32-WROOM-32/ESP32-WROOM-32-AT-V3.2.0.0.zip) on to the board. With this firmware the ethernet connection however does not work at all. The LEDs on the ETH port don't light up. The unit is pretty much dead.

I managed to get the eth port going again by following these instructions: https://github.com/DrJohnM61/poesp32-esphome. This enables the the M5stack PoESP32 to receive an IP address, but the communication with the M5ATOM through the serial link does not work.

Long story short, where can I find the factory preinstalled firmware for the M5stack PoESP32 board, so that I can flash it?

Thanks for your support
Chris