Sometimes fails to submit barcodes

[AndrewBWS]

sometimes Koha will get a barcode from an item on the pad, insert it into the field on the website, but then stop without actually submitting the barcode for whatever action you're attempting. Once this non-submit behavior starts, it persists until the RFID action changes. I've done some testing on this and am fairly certain that the non-submit behavior starts whenever the scanned tags include an item that has been previously processed -- something in the process of dupe-checking the combined processed and unprocessed barcodes and removing the duplicate seems to through off the rest of the process