I don't know if it's a bug, but in my current program I have a Serial.print that prints some data every seconds in the Serial Monitor. So the TX LED is blinking every seconds, until now everything is normal.
But if I close the Serial Monitor, the LED continue blinking for approx 93 seconds, and then stay ON. After a press of the Reset button, the LED is still ON.
Only when I unplug the power (from USB), and plug it back, the LED stay OFF as it should. When I reopen the Serial Monitor, the LED starts blinking every seconds again, as should, and the problem always happen like 93 seconds after I close the Serial Monitor.
Any idea why? Should I check if Serial.available() before the Serial.print? :astonished: