This can happen when the chase blocks drop. The chase has locking devices to keep the block type in place. The chase has 4 sides and has from two to four locks. If the locks on one side come loose the type block letters can become loose and move. This may have been the problem. The old letter press had this problem. They may not have been plates as one suggested above, but block letters..
The section of the press, that holds the type, or block of type in the press on the left side, came or broke loose, during that phase of the printing process, and dropped down. All sheets that went through before the problem was corrected will be the same way. You should have many, till it was corrected. If it had been a sheet out position, then the other "11" numbers would be off of the sheet too. The right "11" numbers are in their correct position. I do disagree with The Error Encyclopedia. All of the district numbers and district seals are all printed at the same time, and not the intaglio type.
I was also wondering what that little downward-facing triangle is in the blank spot on the left. It's on the bill in the first post and the photo in the encyclopedia.
It should be a piece of the armature that normally holds that side of the overprint stamp, touching the surface of the bill with ink on it. Did anyone notice that the OP's bill and the guidebook picture are from the same pack, only 4 notes off? If the guide book note, "113" is the first error, and the position of the broken plate is perfectly stable until "117", then it probably lasted throughout the rest of the pack at a minimum without being discovered. Since the two shown notes are both CU, there should be at least an additional 85 CU error notes from that pack, which obviously ended up in the hands of a coin or currency dealer. Of course there could be far more, some discovered by the same dealer and some that entered circulation and were worn or lost.