The bug
When you want to place a scaffolding next to another that will place it on top of the other and vice versa.
Linked issues
is duplicated by 6
Comments 2
Even so, I find it pretty annoying having the placement swapped, because when you are not flying you have to stand halfway out of the block to build up, and I always forget the swapping. Also, placing a scaffolding piece under another scaffolding piece (this is a bug too, it is hard to come by because scaffolds break when you break the one under them) will instead place it on top, which I actually think is cool.
You have to hold shift to place it at the side of it. This reversed placement was done (as far as I know) to make it easier to build scaffolding bridges.