The barcodes represent different data so the barcodes don't match between the dem and repub ballots. Think of it like a ticket for a concert. The tickets are the same overall but the barcode/QR code information is different because each ticket is carrying a unique number so the barcodes/QR codes are different. If I can find the name of this barcode type, I can decode the data because there will be a complete set of documentation for this barcode standard. The decoded data will reveal the nature of the differences and whether or not the encoding is incorrect. You receive flyers or shopping circulars in the mail right? They're all the same but the address is unique to you and different from your neighbors. This is what is happening here with these ballots.