I am eager to get the fresh parts and see what happened. I do think I'm closing in on the answer, though. As dumb as it sounds, this has been weighing on my mind for a while. I think the answer may be below...
1. The notch in the center of the strut is to hold the squared off section of part N156 - or so it looks in step 24. Notice the placement arrow.
2. If you look closely at step 25 in the red arrow and the bold 24 - that part N156 is pretty much flat against the strut N153. There is a small square piece you can see in step 24 just underneath the letter E. I believe that is what fits in that notch. That would give the extra length needed to fit that rod properly. Again, looking at step 25 closely, the cylinder that juts out seems to be on the left side of the part. Clear, huh?