When using the barcode app and a scanner device (Zebra) I get the following weird behaviour:

First to know: We use I hope a common Barcode nomenclature for weighted products, which is 21.....{NNDDD}, example: 2112345003504, which means: 21 prefix, 12345 product id, 00350 means 0.35kg, and 4 the EAN13 security digit. 

Now the problem: When I scan such a 21-Barcode, which isnt defined for any product and therefore not in our system, it takes the weight anyway and adds it up to the last products I was scanning. That of course produces completely false stocks and I find this behaviour very weird. The barcode app should give me a hint, that the barcode I have just scanned is not existing in my system and should definetely not add the found weight onto any other products stock. 

Anyone experience with that? Thanks much!