QR Code size randomly changes when printed - CAB SQUIX 4 M - JScript programming language

Question

I have a weird issue when printing QR Codes on CAB Squix 4M printer. Randomly happens that the QR Code size changes (will be bigger then normal).

Snippet of the label :

B 21.7,2.0,270,QRCODE,0.48;X-HM://0066F33LTBD61 

The input is always the same number of characters 20.

Examples >

1. X-HM://0066DW8YA0GX6 > normal size
2. X-HM://0066F33LTBD61 > bigger than normal

Can anyone explain me the logic ?