ESP32 blinking TX led when connect dupont cable to negative protoboard line

[j0rd1_123]

I have an esp32 and suddenly when connecting to gpio 12 a cable dupont to negative protoboard line and then i connect the cable usb to my pc the led tx starts to blink fast and it doesnt stop and if i try to upload a sketch it shows an error.. if i connect the same cable but now different gpio ... like 13...5 etc.. esp32 works normally..

i think esp32 is tranferring data to my pc from gpio 12 but only when connect the dupont cable and then the usb to my pc..
but if i change gpio 12 to 13 (connect a dupont cable to protoboard) and then the usb to my pc the esp32 doesnt blink the tx and i can work normally..

i want to know what is the issue.. maybe if i reset the esp32 it will work normally if i use gpio12.. but more than solve the problem i know what the issue is? and understand the issue.. maybe there is a way to know whats wrong with esp32.. or maybe is the line where pin12 is on the protoboard
thanks in advance.

[ESP_Sprite]

GPIO12 is a bootstrap line that changes the flash voltage depending on its level on reset. That may have caused this.