Simple but QR Code not working

Hi,
Wordpress, te plugin and the Android applications are all udated.
Indead, it seems to be very simple to use, but I tried to scan the QR code with two different applications on Android, and none of them have been able to read the QR code.
Both of the two applications told me that the QR code was wrong.
So I understand that you don’t want to have bad evalutation, but I can can do no more than two stars, for the “easy way to use”, but, as it’s not worknig, I won’t go further.