Error Flashing new KCS firmware using ESP32 Download Tool

[kykity]

Hi everyone, I'm new to Kincony products and this forum. I recently bought a Kincony A2V3.1 board to test these products and their integration with Home Assistant.
Once the board arrived, I connected it to my router via LAN cable, but I cannot see any IP address on the A2V3 screen, nor can I find it on my network.
For this reason, I tried to reflash the KCS v3 firmware using ESP32 Download Tool V3.9.2 and entering download mode (turn off → press S2 button → turn on power → release S2).
However, when I press "start" on the ESP32 Download Tool, I get this error:  Geometry Dash

Code:

1 kill
test offset :  0 0x0
case ok
test offset :  0 0x0
case ok
Uploading stub...
Running stub...
[2025-07-12 09:22:45,885][ESP8266Loader_spi[1]][espDownloader.py][line:586][ERROR]: ESP32 Chip stub error esp_stub_and_set_baud.
no log file output ...

I already tested it with different USB cable, different PC and different power supply. But getting always same error.
Here a screenshot from ESP32 Download Tool V3.9.2:

Can you please help me debugging this issue?
regards,
Stefano
Thanks

[admin]

take a photo of your setting screen of esp download tool.