It does appear that the beam is clipping the wall in the carbon and dummy. The target wall is thicker in the carbon target, so that is probably why there appears to be dramatically more clipping in the carbon target.
The ammonia target appears to be positioned well enough to avoid the walls. If you can confirm different encoder values for the dummy and carbon positions that avoid clipping the wall, post them to the log book and we will change them in the target mover program.