If you are scanning EAN13 barcodes on a JM9+ you will need to turn on the 'check digit' setting which is done as follows

 

You may be able to swipe up on the home screen to show the app drawer.

If this does not work tap the app drawer button:

Then access the 'Scan Tool' app

Tap the 'Barcode' tab

Tap 'UPC/EAN'

You'll then find a setting for 'EAN13 Check Send' which needs to be set to 'on'