Zebra TC56 not scanning all QrCodes

Hi, I have a lot of QRCodes like the ones attached to this issue.
I'm not able to scan some type of qrcodes while I don't have problems with other ones.
For tests purposes I'm currently using the DataWedge demo application installed on the device (with Android 6.0) using the 2D Barcode scanner.

08112018053920463.png 08112018054415708.png

What's wrong with my QRCodes? It's a problem with the scanner configuration or the codes are not correctly formatted?

Thank you.
Simone