Update the PRL (Preferred Roaming List) on your device for the ZTE MAX XL
Steps to update the PRL on your Device
Keeping your Preferred Roaming List (PRL) up-to-date can improve your network coverage.
1. From the home screen, tap the Menu key.
2. Tap System Settings.
3. Scroll to and tap System updates.
4. Tap Update PRL and wait until it completes.
5. Tap OK.