I'm not sure if I've found a bug or if I'm missing something so I figured I'd ask here first.
I'm using Illustrator CC on Windows. My goal is to create multiple pattern brushes that align on a path, allowing me to switch from one pattern to the next without the pattern shifting on the path. Not a shift along the path but offset from it. For example if multiple paths are horizontally drawn and aligned vertically then all of the patterns would line up vertically (none higher or lower than the others).
I've created each of my pattern brushes with the grey square elements in the image above. The resulting paths are the blue lines below. As can be seen, the third pattern is shifted much lower along the path and doesn't match up with the other two and I can't for the life of me figure out why. I'm using invisible boxes to try and ensure that the dark central stroke is centered along the path.
I've also noticed that the brushes panel for the third stroke has done something odd with the corner treatment. Maybe this has something to do with it? Any help would be greatly appreciated.