I believe you are correct. Trigger control is something I really need to work on.
There are also times when I get similar groups in the upper right. But I do have a tendency to "ambush the bull". Bad.
Going upper right is the result of anticipating the shot. You are effectively pushing forward with the heel of your hand. You should just be focusing on the front sight whilst applying pressure on the trigger with the shot released at between 5 and 8 seconds.