Okay well the first thing we need to do is get rid of kinguser completely and replace it with the newest supersu because I have seen many cases where kinguser does not work properly. There are a lot of root apps that will work fine with supersu but will malfunction with other superuser apps.
I will provide instructions.
[1] Download my Metropcs stock ROM.
https://www.androidfilehost.com/?fid=24052804347760032
[2] Download UPDATE-SuperSU-v2.46.zip
http://download.chainfire.eu/supersu
[3] Use titanium backup to backup all of your downloaded apps along with your SMS, call logs, WiFi and Bluetooth settings etc... DO NOT BACKUP KINGROOT, KINGUSER, OR CHINESE CHARACTER APP!
[4] Reboot to recovery and press wipe and then select data, cache, dalvik, and system. Do not wipe internal storage or SD card.
[5] Flash the metro stock ROM and supersu zip in that order, and then reboot system.
[6] Setup your Google account and reinstall titanium backup and restore all your user apps (except for WiFi Tether Router) & settings.
(Only restore the stuff that has white or yellow letters. Don't restore anything that has red or green letters. Kinguser and the apps that come with it shouldn't be backed up but if they are, DO NOT RESTORE THEM!)
[7] Reinstall WiFi Tether Router(don't restore it with titanium backup) and then set it up exactly like the OP says. Any settings in the app that are not mentioned, are ones that you DO NOT CHANGE from the default.