Help TWRP not asking to root

[snakyjake]

I followed "[GUIDE] Root & ROM the SGH-T989" and post #3.

I could not get TWRP to ask me to root.

In TWRP, Select Reboot, then System, TWRP will tell you that you are not rooted and ask if you want to root. Use the Swipe bar at the bottom to root then follow the instructions to install SuperSu. Easy peasy.

I did continue on...
I was able to install superuser / busybox. But it doesn't do anything...it is just there.
Titanium Backup says I'm not root.
I flashed superuser twice.

What can I try next?
Not sure if a SIM card lock would create problems.

Samsung T989 (TMobile)
Android 4.1.2

Thanks,
Jake