Then I arranged the long sides of the shapes together via automatic clapping (and I zoomed in to make sure that they are together. I checked the cut time, and it was the same:
If you zoom into the Preview you can see that the lines are not actually overlapping. And you can see that the corners are actually curves. This is because you have a kerf setup.
If you attempt to burn with the shapes directly butted up against each other with a kerf you’ll actually be intruding on the neighboring part with the outward kerf you have setup.
I checked to see if overlapping lines would be removed if you positioned the parts away enough to account for kerf and it did in fact work.