Those would definitely help. Absent that, some guesses are the best we can do.
The beam may be hitting the side of the nozzle due to bad alignment from Mirror 3.
Put a piece of tape over the nozzle and fire a manual pulse. The hole in the tape should be dead center in the middle of the nozzle opening.
Perhaps the tube is not resonating in TEM00 mode, as in a similar problem:
That discussion took a while to eliminate the other possibilities, but the beam tests along the way will show you how to figure out if your laser has the same problem.