arduino motor shield issue

My code below works fine for channel B. The LED's for B alternate as motor B goes from forward to reverse. However, I cannot get motor A alternate. THe LEDs for A light up together and go off together. But I can't find a bug in my code. I've also verified its not the motors, because each works in channel B. What could cause this I wonder? I am using arduino uno and the arduino motor shield.

void setup() {
  pinMode(13, OUTPUT);
  pinMode(8, OUTPUT); 
  pinMode(12, OUTPUT);
  pinMode(9, OUTPUT); 
}

void loop() {
  
  digitalWrite(13, HIGH);
  digitalWrite(12, HIGH);
  digitalWrite(8, LOW);
  digitalWrite(9, LOW);
  analogWrite(11, 200);
  analogWrite(3, 200);
  delay(5000);
  
  analogWrite(11, 0);
  analogWrite(3, 0);
  delay(2000);
  
  digitalWrite(13, LOW);
  digitalWrite(12, LOW);
  
  analogWrite(11, 200);
  analogWrite(3, 200);
  delay(5000);

  analogWrite(11, 0);
  analogWrite(3, 0);
  delay(2000);
  
}

THe LEDs for A light up together and go off together.

Sounds like a short on the motor shield between those two pins.