First and check and see if all cables and antennas are connected correctly and tight.
Next, check on the distance you are away from the inside antenna. You may need to be closer to the inside coverage to receive signal into your device.
If there’s still no improvement, try turning your LTE off on your phone if you have a 3G booster since phones can read 4G instead of 3G most of the time. Check and see if your 3G improves with the amplifier off and when it’s on next to the inside antenna.
At this point if you still see no improvement, a good idea would be to call our technical support at 866-294-1660 or contact our online support at: firstname.lastname@example.org
We are happy to help!