Allow me to explain the problem from the very beginning...
a) I just rooted by Note 2 using the CF-Autoroot and Odin method, and then installing
SuperSU from the Play Store. It worked flawlessly!
b) Then I tried to flash MJ5 bootloader using Dr Ketan's method here using Odin:
I got the fail message and the phone went into "Firmware upgrade encountered an issue.
Please select recovery mode in Kies & try again" error mode
c) I did a recovery using kies as suggested. Phone came back to normal.
d) After this I tried the Odin and CF-Autoroot method again. Now Odin says Pass!,
but the phone is still unrooted!
e) Then I tried Ketan's Multitool and renamed the knox files to knox.bak and rooted with it.
g) Then again I used the Multi tool and tried to remove the knox files and rooted with it.
This time it worked. After first restart, it says root successful.
But after some time, it again goes back to "phone doesn't have root access"
and becomes unrooted automatically.
And this has happened many times.
What should I do to keep the phone rooted?
What's causing it to become unrooted automatically?
Thanks for your help.