CTC not working with external T0/T1 signals in Arduino UNO and ATmega328P

Hi, I think there is a bug in Arduino UNO and ATmega328P when using Timers/Counters 0 and 1 in CTC mode with external input on T0/T1: it counts from 0 to 1 and then it stops working.
I tested the code on real hardware and it works fine.
Furthermore, all other modes (Normal and PWM) of the simulator are working properly.

Hi.
Which version are you using?

Also if you have a simple circuit and code to test it would be helpful.

Hi, I'm using version 0.4.15.

This is the sample code:

Code:

void setup(){
   pinMode(4,INPUT_PULLUP);

   TCCR0A = 0b00000010;
   TCCR0B = 0b00000110;
   
   OCR0A = 20;
   
   Serial.begin(9600);
}

void loop(){
   Serial.println(TCNT0);
}

It should count up to 20 on falling edge of pin 4 and then reset. If you use the internal clock with prescaler instead it counts regularly.

Issue solved at Rev 275.